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JANUARY 10, 1979 



THE 



NAUTILUS 



ISSN (K)28-i:544 



Vol. 93 




No.l 



A quarterly 

devoted to 

malacology and 

the interests of 

conchologists 



Founded 1889 bv Henry A. Pilsbry. Continued by H. Burrington Baker. 
Editor-in-Chief; R. Tucker Abbott 



EDITORIAL COMMITTEE 



CONSULTING EDITORS 



Dr. Arthur H. Qarke, Jr. 
Division of Mollusks 
National Museum of Natural History 
Washington, D.C. 20560 

Dr. William J. Clench 
Curator Emeritus 
Museum of Comparative Zoology 
Cambridge, Mass. 02138 

Dr. William K. Einerson 
Department of Living Invertebrates 
The American Museum of Natural History 
New York, New York 10024 

Mr. Morris K. Jacobson 
Department of Living Invertebrates 
The American Museum of Natural History 
New York, New York 10024 

Dr. Aurele La Rocque 
Department of Geology 
The Ohio State University 
Columbus, Ohio 43210 

Dr. James H. McLean 
Los Angeles County Museum of Natural History 
900 Exposition Boulevard 
Los Angeles, California 90007 

Dr. Arthur S. Merrill 
Woods Hole Biological Laboratory 
National Marine Fisheries Service 
W(X)ds Hole, Massachusetts 02543 



Dr. Donald R. Moore 
Division of Marine Geology 
School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami. Florida 33149 

Dr. Joseph Rosewater 
Division of Mollusks 
U. S. National Museum 
Washington, D.C. 20560 

Dr. G. Alan Solem 

Department of Invertebrates 
Field Museum of Natural History 
Chicago, Illinois 60605 

Dr. David H. Stansbery 
Museum of Zoology 
The Ohio State University 
Columbus, Ohio 43210 

Dr. Ruth D. Turner 
Department of Mollusks 
Museum of Comparative Zoology 
Cambridge, Mass. 02138 

Dr. Gilbert L. Voss 
Division of Biology 

School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, Florida 33149 

Dr. Charies B. Wurtz 
3220 Penn Street 
Philadelphia, Pennsylvania 19129 



EDITOR-IN-CHIEF 

Dr. R. Tucker Abbott 
American Malacologists, Inc. 
Box 4208, Greenville, Delaware 19807 

Mrs. Horace B. Baker 
Business and Subscription Manager 
11 Chelten Road 
Havertown, Pennsylvania 19083 



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THE 

NAUTILUS 

Volume 93, number 1 — January 10, 1979 

ISSN 0028-1344 



CONTENTS 



William K. Emerson and Anthony D'Attilio 

Six New Living Species of Muricacean Gastropods 1 

William K. Emerson and William E. Old, Jr. 

Scaphella contoyensis, a New Volutid (Gastropoda) from East Mexico 10 

W. Stephen Thomas 

A Biography of Andrew Garrett, Early Naturalist of Polynesia: Part 1 15 

Douglas S. Jones 

The Nemertean, Malacohdella grossa, in the Ocean Qushog, Arctica islandica (Bivalvia) 29 

Gary L. Pace, Ernest J. Szuch and Richard W. Dapson 

Depth Distribution of Three Gastropods in New Mission Bay, Lake Michigan 31 

Dorothy Blanchard and Lowell L. Getz 

Arion subfuscus in Southeastern Michigan 36 

David Pool and Jack McCullough 

The Asiatic Clam, Corbicula manilensis, from Two Reservoirs in Eastern Texas 37 

J. Roy Robertson 

Evidence for Tidally Correlated Feeding Rhythms in the Eastern Mud Snail, Ilyanassa obsoleta .... 38 

Edward B. Hatfield 

Food Sources for Anachis avara (Columbellidae) and a Discussion of Feeding in the Family 40 

Jean Ann Nichols and J. Roy Robertson 

Field Evidence that the Eastern Mud Snail, Ryanassa obsoleta. Influences Nematode Community 
Structure 44 

Publications Received ii News ii 



WANTED -OLD SHELL BOOKS 

Will pay good prices for libraries second- 302--239-2025) or write: R. Tucker Abbott, 

hand books and reprmts on mollusks, shells Amencnn Mahwohgist,. Inc.. P. 0. Box 4208. 

and conchology. Back numbers of The NauU- Greenville. DE 19807. Free appraisals. 
lus. vols. 40-71 wanted, $1.50 each. Phone (1- 



PUBLICATIONS RECEIVED 



Houbrick, Richard. S. 1978 (Dec. 15). The Family Centhiidae 
in the Indo-Pacific. Part 1: The Genera Rhuuirlnri.% 
Pseudovertagus and Clavocerithium. Monographs of Marine 
Motlmca. No. 1. pp. 1-130. 98 pis. 3 in color. Taxonomic 
revision, biologj'. anatomy, phylogeny and geographical 
distribution of 47 living and fossil species. American 
Malacologists. Inc. $17..50, postage paid. 

Chatfield. .June E. 1978. Welsh Sea-fhells. 44 pp.. 90 figs. (20 in 
color. Paperback. National Maseum of Wales. Cathays Park. 
Cardiff. U.K. CFl 3NP. Remit U.S. $.3.00 or jC 1..50 sterling. An 
e.xcellent little guide with 90 common shore species. 

Goryachen. V. N. 1978. Gastropod Mollusks of the genus Sep- 
tunea Rciding of the Bering Sea. 90 pp.. 25 pis. Science 
Press, Moscow (in Russian). 

The Pariah, no. 4. Sept. 1978. Edited by Jerr>' C. Walls. 8 pp. 
Contains review of Harpidae (.J. G. Walls), note on Cin>raea 
thoninsi (P. W. Clover) and remarks on Conns patae (J. G. 
Walls). Available for 50 cents. P.O. Box 42. Hightstown. N.J. 
08520. 

Popenoe. W. P. and R. M. Kleinpell. 1978. Age and 
Stratigraphic Significance fur Lyellian Correlation of the 
Fauna of the Vigo Formation. Luzon. Philippines. Occ. 
Papers California Acad. Sci.. no. 129. pp. 1-173. 18 pis.. 1 
Uble. 



Saul. Louella R. 1978. The North Pacific Cretaceous Trigoniid 
Genus Yaadia. Univ. Calif. Publ. in Geol. Sci.. vol. 119: 1-65, 
12 pis. $7.25. Excellent account. 

Zhengzhi. Dcjug. 1976. On Three New Species of the Genus Oc- 
topus from the Chinese Waters. Studia Marina Sinica, no. 
11. pp. 211-215. (0. nanhaiensis, 0. striolatus and 0. 
yuanydongensis new species). 

Zhengzhi. Doug. 1978. On the Geographical Distribution of the 
Cephalopods in the Chinese Waters. Oceanologia et Lim- 
nologia Sinica. vol. 9, no. 1. pp. 108-116. 

Wu, Shi-Kuei and Nancy Brandauer. 1978. Natural History 
Inventory of CoUirado. 2. The Bivalvia of Colorado. Univ. 
Colorado Museum. Boulder. CO 80.309. 60 pp. 87 figs., keys. 

Giese, Arthur C. and John S. Pease, (editors). 1977. Reproduc- 
tion of Marine Invertebrates. Vol. 4. Molluscs: Gastropods 
and Cephalopods. 369 pp. Academic Press. HI Fifth Ave.. 
N.Y.. NY 10003. Hardback. .$38.00. An excellent, well- 
illustrated and w^ell-documented account by competent 
workers- Includes recent reviews of reproduction on Pro- 
sobranchia (H. H. Webber). Opisthobranchia (R. D. 
Beeman); estuarine Basommatophora (A. J. Berry); 
Nautilus (Norine Haven); Squids (J. M. Arnold and L D. 
Williams-.^mold): and Octopoda (M. J. and J. Wells). 



NEWS 



A.M.r. - W.S.M.. Joint Mpptiivj 
Symposium on the Life Histories of Mollusks 

Papers on any aspect of molluscan life histories 
will be considered for presentation at a sym- 
posium to be held during the joint meeting of the 
Western Society of Malacologists and the Amer- 
ican Malacological Union in Corpus Christi, 
Texas, 5-11 August 1979. Presentations should 
be concerned with an aspect of the reproduction, 
development, growth, or population dynamics of 
mollusks. Theoretical papers on the evolution of 
life history traits of mollusks are also invited. 
Opportunity for publication of abstracts or full 
length versions of papers pre.sented at the sym- 
posium will be provided. Further information 
and a Call for Papers is available from: 

David R. Lindberg 

Invertebrate Zoology 

California Academy of Sciences 

Crt)lden Gate Park 

San Francisco, CA 94 118 



UNITAS MALACOLOGICA 

The international society of professional 
malacologists (formerly the Unitas Malacologica 
Europaea) is now open to all scientists interested 
in living or fossil mollusks. The President is Dr. 
Jean M. Gaillard. Museum d'Histoire Naturelle, 
55 rue de Buffon, F-75005 Paris, France, to whom 
readers should write concerning the next and 
Seventh International Malacological Congress. 
Tliese meetings will be held August 31 (registra- 
tion) to September 6, 1980, on the Mediterranean 
coast of France near the "Laboratoire Arago". 
Secretary of the Unitas Malacologica is Dr. 
Oliver E. Paget, Naturhistorisches Museum, 
Burgring 7, A-1014 Vienna, Austria. 



Vol. 93(1) Januaty lU, 1979 THE NAUTILUS 1 

SIX NEW LIVING SPECIES OF MURICACEAN GASTROPODS 



William K. Emerson 

American Museum of Natural History 
New York, N. Y. 10024 



and 



Anthony D'Attilio 

Natural History Museum 
San Diego, California 90112 



ABSTRACT 



The following neiv species of gastropods referable to the Muricidae are 
described: Pteropurpura benderskyi from West Afiica: Favartia guamensis and F. 
dorothyae//'o»( the western Pacific, and F. elatensis/n*m the Red Sea: Murexiella 
mactanensis from the we^em Pacific; and Siphonochelus radwini from the 
western Atlantic. A recently described species. Murexiella martini Shikama, 1977, 
from the western Pacific, is illustrated and a supplementary description is given. 
Dermomurex neglecta (Habe and Kosuge, 1971), from the western Pacific, is il- 
hi.sf rated and a tran.slation of the original description is provided. 



At the time George E. Radwin and the junior 
author were preparing the text for "Murex Shells 
of the World, An Illustrated Guide to the 
Muricidae" (Radwin and D'Attilio, 1976), a 
number of taxa were recognized by them as new 
species. Fifteen of these species were described in 
an appendix to their book. Although they in- 
tended to describe elsewhere several other taxa 
that were received after the text of the book was 
completed in mid-1971, the tragic and untimely 
death of Dr. Radwin in 1977 terminated their 
joint venture. 

At the request of the junior author, the senior 
author has joined him in the preparation of the 
present report, which was based in part on 
preliminary notes prepared jointly by D'Attilio 
and Radwin for two of the taxa described herein. 
The new taxa are classified largely according to 
the system followed by Radwin and D'Attilio 
(1976). 

ACKNOWLEDGMENTS 

We are grateful to the following collectors for 
the loan and/or donation of specimens: Israel 
Bendersky, L. J. Bibbey, Albert E. Deynzer, 
Francis Fernandez, Dorothy and Robert 
Janowsky, Leo Kempczenski, Don Pisor, and 
Eugenia Wright. Dr. Joseph Rosewater of the 
Department of Invertebrate Zoologv', National 
Museum of Natural History, Smithsonian Institu- 
tion and Dr. H. K. Mienis of the Zoological 
Museum, Hebrew University of Jerusalem lent 



additional material. Dr. Emily H. Yokes of the 
Department of Geology, Tulane University, pro- 
vided data and the photographs used to illustrate 
figures 17 and 18. Masao Tabakotani of Bronx- 
ville. New York, generously contributed a 
translation of Japanese te.xt. William E. Old, Jr. 
and G. Robert Adlington of the American 
Museum of Natural History kindly provided 
respectively, technical assistance and the 
photography. 

INSTITUTIONAL ABBREVIATIONS: 

AMNH = American Museum of Natural History, 

New York, New York 
HUJ =Zoological Museum. Hebrew University of 

Jerusalem, Israel 
NMNH = National Museum of Natural History, 

Washington, D.C. 
SDMNH =San Diego Museum of Natural 

History, San Diego, California 

Family Muricidae 

Subfamily Muricinae 

Genus Deimomurex Monterosato, 1890 

Type species: Murex scalarinus Bivona-Bemardi , 1832 

( = M. xcalaroides Blainville, 1829), by original designation. 

Dermomurex neglecta (Habe and Kosuge, 1971) 

Figs. 17. 1,^ 

"Description: Shell distinguished by its varices, 
five in number, in each whorl. They are broad 
and somewhat prosocline at the shoulder to 



2 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



suture position. Whorls between varices are 
sculptured by numerous fine spiral striae so that 
it looks almost smooth. Siphonal fasciole is 
outstanding and umbilicus is open. Shell white 
with slight yellowish tinge in color." 

"This species is distinguished for the shape and 
varices. Actually two specimens are known, both 
caught in South China Sea and brought back to 
the port of Kaohsiung, Taiwan." (Translation of 
the Japanese text, courtesy of M. Tabakotani .) 

Meaaurementu: Holotype, length 22.5 mm, 
width 11.2 mm; specimen illustrated herein, 
length 20 mm, width ll.(X) mm. (Wright collec- 
tion). 

Type locality: "South China Sea", fide Habe 
and Kosuge (1971, page 7). Here restricted to off 
Bohol Island, Philippines. 

Material examined: 1 specimen, off Balicason, 
Bohol Island, Philippines, in 366 meters, Eugenia 
Wi'ight collection. 

Remarks: At the suggestion of Dr. Emily H. 
Yokes, we have presented here a translation of 
the description of this poorly known western 
Pacific taxon, together with photographs of a 
specimen from the Philippines (figures 17, 18), 
which along with another one, had been sent to 
her for identification. Although this species was 
originally described as Phyllocoma neylecta by 
Habe and Kosuge (1971, p. 7, text figure), it is 
referable to the genus Dermomurex and is the 
first Recent record of the genus (sennu i^trirto) in 
the Indo-Pacific. Yokes (1975, p. 129) cited this 
record based on the Philippine specimens which 
were thought to represent an undescribed species. 
She pointed out (1975, op. cit.) that the specimens 
lack apertural denticulations on the outer lip, in 
contrast to the previously known representatives 
of Dermomurex (i^emu stricto). According to Dr. 
Yokes (in litt.) the present species is a probable 
descendent of Dermomurex arutirostatii^ (Wanner 
and Hahn, 1935, p. 254, pi. 19, figs. 8-10) from the 
Miocene of Java. 

Subfamily Ocenebrinae 
Genus Pteropurpura Joussenume, 1880 
Type species: Murex macroptents Deshayes, 1839, by original 
designation. 



Pteropurpura benderskyi, n. sp. 

Figs. 1.2.19 

Des^ciiptioii: Shell small for genus, attaining 23 
mm. in length, trigonally fusiform in appearance. 
Spire acute and high, with l'/2 polished, brown 
nuclear whorls, followed by 5 convex, postnuclear 
whorls; suture distinct, not strongly impressed. 
Body whorl moderate in size. Aperture ovate, 
with peristome entire and mostly erect, except 
for the posterior portion of left side in the 
parietal region. Siphonal canal broad, sealed (ex- 
cept at the recurved, tapering distal end), 
moderate in length and accommodating the siphon- 
al fasciole. Body whorl with three winged varices; 
each varix with webbing between prominent 
spine-points. A medial costate ridge and two less 
prominent flanking costae intervene between 
each pair of consecutive varices. Spiral sculpture 
of numerous primary and secondary cords ex- 
tending over body and siphonal canal. Primary 
cords strongest on dorsal surfaces of the spines. 
Spine at shoulder margin longest; body with a 
less prominent spine medially placed and with a 
minor spine at the base of body whorl and on the 
upper portion of siphonal canal. Leading, or ven- 
tral sides, of varical spines weakly open; last 
varix with leading edge sculptured with fine, low 
undulating lamellae and with some grovrth lines 
raised at intervals to give a somewhat scabrous 
texture to the surface. Shell tan to dark-brown, 
paler on the varical surfaces; aperture off-white 
and porcelaneous. Operculum: The morphology is 
typically ocenebrinean, as described by Radwin 
andD'Attilio(1976,p. 111). 

Radula: Radular dentition is similar in morph- 
ological characters to those of the type species of 
Pteropurpura, P. macroptera (Deshayes, 1839); 
consult the radular illustrations of the Deshayes' 
taxon (Rjidwin and D'Attilio, 1976, p. 131, fig. 81) 
with the basal and frontal views of a rachidian 
and a frontal view of a lateral tooth of the pre- 
sent species (figure 19 herein). 

Measurements: Holotype, length 23 mm, width, 
including varices 13.9 mm; smallest paratype (SD 
MNH no. 72626). 17.7 mm in length. 



FIGS. 1 and 2, Pteropurpura bendersl<yi n. up., holotmw. AMNH lK.iHl9. X.l 3 and 4, Favartia dorothyae n. sp.. holotype. AMNH 
183821. X.l. 5 and 6, Favartia rosea Hahe. 1.961. .Janowsky CDllection. tmirled in Kii Channel. Wnkayama Prefecture. .Japan, in U6 
meters. X.l. 7 mid 8, Favartia mactanensis n. sp.. holotype. AMNH 1871H6. X.l. 9 and 10, Murexiella martini Shikama, 1977, SDMNH 
72627, Bohol Islattd, Philippines, X2. (Stated enlargements are an appronmalion) 



Vol. 93(1) 



January 10. 1979 



THE NAUTILUS 3 



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January 10, 1979 



Vol. 93(1) 



Tif})c lornlity: Off Luanda, Angola, Africa, 
dredged in 5<l meters, sandy bottom, July 15, 1977, 
FYancis Fernandez collector. 

Material examined: Holotype AMNH 183819, 
from type locality, 1 paratype SDMNH 72626, ex 
Bendersky collection, and 1 paratype, Janowsky 
collection, hnjth from off Luanda, Angola, dredged 
in 80 meters, February 10, 1977. 

Remarks: Until the discovery of this new- 
species, only one living representative of this 
genus was knovra to occur in the Atlantic Ocean. 
Ihe other living Pteropurpura are found in the 
northern Pacific, with three in northwestern 
waters (largely off southeastern Japan) and with 
five in northeastern waters off California and 
northwestern Me.xico (see Radwin and D'Attilio, 
1976, pp. 129 to 133). The present species (figures 



1. 2) differs from P. bequaeni (Clench and Pe'rez 
Farfante, pi. 21, figs. 1, 2, 1945), which ranges 
from North Carolina to the Dry Tortugas, in 
several characteristics (see comparative data in 
table 1). The two taxa clearly represent twin 
species, or cognates, separated by the present ex- 
panse of deep water of the Atlantic Basin. 

Subfamily Muricopsinae 
Genus Faimiia Jousseaume, 1880 
Type species: Murei breinculus Sowerby. 18.34. by nripinal 
de.signation. 

Favartia guatnensis n. .sp. 
Fips. 11.12 

Drxcription: Shell small, attaining 8 mm in 
length, fusiform. Characterized by strong rugose 




FIGS. 11 (!/»/ 12, Favartia guamensi.s n. up., halnti/pe. SDMXII ;av.5. X.r l.S ami 14, Favartia elatensis >i. sp.. pamtifpe. 
SDMNH 6M5ia. X.5. 15 and 16, Favartia dorothyae n. .fp.. parati/pc- AMNH lS^i82:i. X.i. 17 and 18, Dermomurex neglecta 

(Hahe and Koxntir. 1!)7II: Wnnht culU'ctiiDi. (iffBulml Island. Philippines. XJ. (Stated rnlniyrnii-nts art' an apprariniatitin) 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 



TABLE 1. Comparative diagnostic charm-ters of Pteropurpura bequaerti and Pt. benderskyi 



Pteropurpura bequaerti 

Maximum size 42 mm 

Numbers of whorls 6 to 7 

Outer lip crenulated 

Varices blade-like 

Axial sculpture a single, low knob 

Spiral sculpture terminates in toothlike points on varical 

margins 

Color gray-white; tip of siphonal canal suffused 

with purple-brown. 



sculpture. Protoconch low, smooth with IVz 
whorls; followed by 5 convex whorls; suture deep 
but obscured at varices; spire well elevated. 
Aperture ovate; peristome weakly erect; anal 
sulcus deep, constricted in front into a closed 
channel. Siphonal canal with rostrate fasciole, 
broader above, tapering distally, slightly recurved 
with a narrow sinuous opening. Shell with 5 
strong, spiral cords, squarish in cross-section and 
with an additional cord on the canal; cords 
crossed by strongly elevated fimbriae; fimbria- 
tions extend into the interspaces. Spiral cords 
with a strong central groove, crossed by fine 
lines, and with fimbriae forming strong, canopy- 
like scales; scales further interrupted axially by 5 
to 8 fine grooves; scales scalloped on terminal 
edge. Varical flanges elevated and terminally 
wavy; early whorls with 6 varices; body whorl 
with 4 varices. Color of shell deep orange-red, 
ranging to yellow in the four specimens ex- 
amined. 

Measurements: Holotype, 7.5 mm in length; 
largest paratype, 7.7 mm in length; smallest 
paratype, 6.6 mm (Pisor collection). 

Type locality: Off Orote Cliffs, Guam, Marianas 
Islands, in 18 to 21 meters under large boulders, 
5-1-1977, Leo Kempczenski collector. 

Material examined: Holotype, SDMNH no. 
72625; 1 paratype, Leo Kempczenski collection 
and 1 paratype, AMNH no. 183820, all collected 
by Leo Kempczenski from type locality; 1 
paratype from type locality, Don Pisor collection; 



Pt. benderskyi. n. sp. 

23 mm 

5 (or more ?) 

not noticeably crenulated 

spine-like projections 

medial costae and 2 less prominent flanking costae. 

varical margins extended into 4 broad-based, spiny 
terminations, with scabrous lamellae on ventral sur- 
face. 

tan to dark-brown, paler on ventral surface 



1 paratype from coral rubble, in 18 meters, SCUBA 
diving, 1977, A. Deynzer collection. 

Remarks: The small size of the present species 
(figures 11, 12), complemented by the develop- 
ment of elaborate sculpture, the elongated body, 
and the rich coloring serve to distinguish this 
taxon from any of its congeners. 



Favartia dorothyae, n. sp. 

Figs. 3. 4. 15,16 

Description: Shell small for genus, attaining 9 
mm in length, broadly fusiform; spire elevated 
but small in proportion to body whorl; pro- 
toconch of l'/2 whorls; post-nuclear whorls 6 in 
number; suture distinct. Body whorl obese, with 
a small ovate aperture; anal sulcus weakly- 
developed. Lower half of inner lip erect, adherent 
above; outer lip crenulated and sculptured within 
by 7 long lirae. Anterior end of columella or- 
namented by a small tooth. Siphonal canal broad 
above, tapering and distally recurved; siphonal 
fasciole rostrate. Body whorl with 5 major cords 
and with one major cord on canal; each cord sub- 
divided by 4 or 5 incised lines. Three secondary 
cords situated above the major cord at shoulder. 
A secondary cord present on the body whorl 
below the second and third cords. A major cord 
appears on the canal with secondary cords above 
and below it. Additional minor spiral cords pre- 
sent on the body as well as over the shoulder. 
Five varices form the axial sculpture. Starting at 



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January 10. 1979 



Vol. 93(1) 



each varical margin, the cords ascend to the 
strongly developed varix where they terminate 
and are recurved distally. The leading side of 
each varix bears 7 or 8 fimbriae which develop 
into scaly sculpture over the whorls. The shell 
color ranging from warm-white to carmine with 
the early whorls golden-hued; characteristically 
with the cx)lumella, the dorsal and ventral sides 
of the canal, and the base of the body whorl are 
all strongly colored a rosy pink. 

Measurements: Holotype 15.9 mm in length, 
width 9.6 mm; smallest paratype (lacking a 
mature siphonal canal) 13.7 mm (AMNH 183822); 
largest paratype, 16.2 mm (SDMNH no. 72624). 

Ti/pe locality: Off Punta Engano, Mactan 
Island, Philippines, in about 30 meters, (obtained 
in tangle or gill nets), 1977, ex Dorothy and 
Robert Janowsky collection. 

Material examined: Holotype AMNH 183821 
(figures 3, 4), and three paratypes AMNH 183822, 1 
paratype SDMNH 72624 (figures 15, 16, AMNH 
183822a); 3 paratypes, Janowsky collection; 1 
paratype Leo Kempczenski collection ; all from the 
type locality. Three specimens, Panglao, Bohol 
Island, Philippines, in trap, 1977-1978, A. Deynzer 
collection. 

Remarks: This species (figures 3, 4, 15, 16) with 
its distinct apertural coloration and delicate 
frostlike sculpture may be easily distinguished 
from the following congeners: F. marjorae 
(Melvill and Standen, 1903), to which it bears 
some resemblance, by comparison with a 
photograph of the holotype in Radwin and D'At- 
tilio, 1976, fig. 95, p. 150. F. marjorae, which has 
a less swollen body and a higher spire, is grey in 
color and occurs in the Persian Gulf. F. balteata 
(Sowerby, 1841) from the western Pacific has a 
more strongly sculptured shell, with well- 
developed black squarrose varices, and has a 
brown shell with a red aperture. F. salmonea 
(Melvill and Standen, 1899) has a comparatively 
higher spire, possesses a decided gap between the 
body cords and those on the canal, and is pale 
reddish orange, darkest at the varices. It has not 
been reported from the northern area of the 
western Pacific. F roaea Habe, 1961, (herein il- 
lustrated, figures 5, 6), from southeastern Japan, 
has a larger (23 mm), fleshy orange to yellow col- 



ored shell, with the varical areas conspicuously 
more rounded (swollen), and the surface not 
noticeably scabrous. 

Favartia elatensis n. sp. 

Figs, la u 

Description: Shell small for genus, attaining 8 
mm in length, fusiform; spire high; protoconch 
1'-: rounded whorls, followed by 5 post -nuclear 
whorls; suture distinct. Aperture ovate, outer lip 
strongly undulate reflecting the dorsal sculpture; 
inner lip adherent; anal sulcus broad and simple; 
canal moderately long, narrowly open, tapering, 
weakly recurved, siphonal fasciole moderately 
developed. Axial sculpture strong with growth 
lines developing into widely spaced lamellae; 
vaulted scales formed by expansion of lamellae 
over the spiral cords. Six varices on post-nuclear 
whorls of spire; four on body whorl. Varices 
crossing at shoulder diagonally onto contiguous 
whorl. Spiral sculpture of 6 squarish and knobby 
cords on body whorl, with one cord, on the canal; 
cords grooved spirally, but dividing somewhat ir- 
regularly into unequal widths, to form unequal 
scaly ornamentation. Cords at the varical 
margins expanded into lobes; final varix with a 
recurved margin. Varical areas of shoulder ex- 
tending into lobes with vaulted edge on leading 
side. Shell color uniformly fleshy white. 

Measurements: Holotype 7.8 mm in length, 3.9 
mm in width; largest paratype, 7.9 mm in length 
(SDMNH no. 63254a, figures 14, 15); smallest 
paratype (immature) 4.2 mm (HUJ no. 10.202/8). 

Tt/])e locality: Elat, Gulf of Elat, Israel, 
29°32'-29°31' N., 36°58'-36°59' E., in 190 
meters from grab sample, October 8, 1965. 

Material examined: Holotype and 7 paratypes 
HUJ 10.202/8 fix)m the type locality; 2 paratypes 
SDMNH 63254, ex HUJ 10.202/RS-18, Elat, Gulf of 
Elat, 29°32'-29°31' N., 36°58'-36°59' E., in 190 
meters; 1 paratype AMNH 183823, ex HUJ 
10.204/1. Elat, Gulf of Elat. 29°31'-29°32' N.. 
34°58'-36°59' E., in 250 meters, October 8, 1965; 8 
paratypes, HUJ 10.203/9 Elat, Gulf of Elat, 
29°3r-29°32' N., ;34°58'-34°59' E., in 80 meters. 

Remarks: The presence of squarely-formed 
spiral cords terminating in lobed projections, and 
the relatively small size of the shell (figures 13, 



Vol. 93 (1) 



January 10. 1979 



THE NAUTILUS 



14) serve to distinguish this species from others 
in the genus. This species is presently knowTi only 
from the Gulf of Elat. Although Recent Favartia 
are not recorded in the Mediterranean, some 
Indo-Pacific species with shells larger than that 
of F. elatensis occur intertidally or in shallow 
depths elsewhere in the Red Sea. 



Genus Murexiella Clench and Farfante, 1945 
Type species: Miirex hidalgoi Crosse. 1869. by original 
designation. 

Murexiella mactanensis n. sp. 

Figs. 7. 8 

Description: Shell medium-sized for genus, at- 
taining 22 mm in length; biconically fusiform; 
spire elevated, with 5 convex whorls; protoconch 
dense white and with suture impressed. Aperture 
broadly ovate; peristome erect, more weakly 
elevated on the left posterior side; margin of 
outer apertural lip wavy, with the 5 undulations 
reflecting the presence of the external cords; anal 
sulcus weak; si phonal canal moderately long, nar- 
rowly open; tapering tube-like and strongly 
recurved; siphonal fasciole strong, spaced some 
distance from body sculpture. Axial sculpture of 
5 erect varices terminating distally as open 
spines of moderate height; final varix set-back 
from aperture, bent back and with the leading 
side richly scabrous; scabrous lamellae on leading 
side of all varices to the margin of each varix: in- 
tervarical area with weaker lamellae or with 
lamellae developing into scales. Spire with 6 
varices, the varices more weakly erect crossing 
the shoulder diagonally and continuing on to the 
varix of preceeding whorl. Body whorl with 5 
spiral cords; cords nearly erect on varices and 
temiinate as upturned spines. Spines at shoulder 
longest; the first two paired, followed by the re- 
maining 3; spines open, marginally not or- 
namented and on the final varix broadest distally 
with the edges recurved on the leading side; 
spines subdivided lengthwise by incised lines into 
2 or 3 unequal areas. Minor cords situated be- 
tween large ones, with a gap between the last cord 
on the body and the spinal cord on the canal. 
Shoulders ornamented, notably on the final varix, 
with a short lobe having 3 or 4 pointed spines. 



Shell color: on the holotype, the spire, inter- 
varical areas, and fasciole flesh-pink, darkest 
towards the apex; varical areas white, especially 
terminally: aperture white. In the paratypes, the 
amount of the flesh-pink coloration varies in in- 
tensity and location on the shells. 

Memurements: Holotype 21.7 mm in length, 
width (including spines) 14.3 mm; smallest 
specimen (4 post -nuclear whorls; Pisor collection), 
length 12.9 mm. 

Type locality: Off Punta Engano, Mactan 
Island, Philippines, in about 30 meters (obtained 
in tangle or gill nets), 1977, ex Dorothy and 
Robert Janowsky collection. 

Material examined: Holotype AMNH no. 187186 
(figures 7, 8); 1 paratype Panglao, Bohol Island, 
Philippines, in about 180 meters, 1977, Albert 
Deynzer collection; 1 paratype SDMNH 7:3800 (ex 
Pi.sor collection) and 1 paratype Don Pisor collec- 
tion, both Bohol Straits, Philippines, in about 50 
meters. 

Remarks: The present species, characterized by 
having the 5 varices terminating in simple, unor- 
namented spines, may be assigned to Murexiella 
(sensu stricto), based on the typological genus- 
group concept of Murexiella Clench and Pe'rez 
Farfante, 1945 (see Radwin and D'Attilio, 1976, p. 
155-161). Several western Pacific species were 
assigned by Ponder (1972) to Murexiella. which 
he regarded as a subgenus of Favartia. These 
other taxa differ from the new species by their 
closer relationship to Favartia (sensu stricto). 
Comparison can be made with the Indo-Pacific 
species F. salmonea (Melvill and Standen, 1899) 
and F. voor-unndei Ponder, 1972, in which the 
body whorl and sculpture are somewhat similar. 
They lack, however, well -developed spines with 
connecting webbing, characters that serve to 
distinguish taxa referable to Murexiella (sensu 
strict(i)- This new species, together with the one 
following, brings to two the number of distinctive 
Murexiella recognized recently in the central 
Philippines. 

Murexiella martini Shikama, 1977 

Figs. 9, 10 

Supplemental description: A slender fusiform 
shell, attaining 28 mm in height (holotype); spire 



8 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 





19 



FIG. 19. Pteropurpura benderskyi n. xp., radular dentition 
(drawirigs by Anthony D'Attilio); greatly enlarged. 



well -elevated, with a protoconch of 1"4 whorls, 
followed by 6 post-nuclear whorls; body whorl 
large, strongly spined at shoulder; suture im- 
pressed. Aperture ovate, peristome entire and 
strongly elevated; sulcus shallow and broad; 
outer lip with 4 extended, lobe-like crenulations 
reflecting the dorsal spiral sculpture. Siphonal 
canal narrowly open, broad above, strongly 
recurved, tapering axially and tube-like distally, 
with fasciole formed by terminations of the two 
previous canals. Body whorl with 3 spinose 
varices; varical margins thick, erect and continu- 
ing nearly midway to the intervarical area; basal 
varix crossing the shoulder diagonally and ex- 
tending to the previous whorl. Four strong spiral 
cords, one at shoulder separated by a gap from 
the group of 3 below; cords terminating in long 
moderately open spines at the varices; spine at 
the shoulder longest, those below about ' 2 as 
long; cords subdivided by 3 to .5 incised lines. 
Spines connected by a flangelike web ornamented 
with a scabi-ous lamellate surface on the leading 
side; varical webbing with one .small, medial cord 
and with a weakly defined cord on either side of 
the central cord. Scaly lamellae on entire surface 
of the shell, exclusive of the canal, and with mo.st 
prominent lamellar development on the raised 
cords and .spines. Shell pale-brown ochre, lighter 
dorsally on the cords and spines, darker brown 
on the open inner surface of the cords and on the 
varical margins; aperture and peristome translu- 



cent whitish. Color somewhat variable among the 
10 specimens examined. 

Measurements: Largest specimen examined 
26.6 mm in length, width (excluding spines) 9.5 
mm; smallest specimen (lacking mature siphonal 
canal) 18 mm in length, width (e.xcluding spines) 
7.6 mm, Ribbey collection. 

Type locality: Off C€bu Island, Philippines. 

Type depository: Personal collection of Dr. 
Tokio Shikama, Yokohama, Japan. 

Material examined: Figured specimen SDMNH 
no. 72627 (figures 9, 10) and 1 other specimen, 
Bohol Island, Philippines, I.^o Kempczenski col- 
lection; 3 specimens from off Punta Engano, Mac- 
tan Island, Philippines Islands, Janowsky collec- 
tion; 1 specimen, Mactan Channel, Philippines, in 
tangle-trawl, Bibbey collection; 1 specimen 
AMNH no. 183818, from Samar Island, Philip- 
pines, ex Bibbey collection; 2 specimens, Panglao, 
Bf)hol Island, Philippines, in trap, 1977-1978, 
Deynzer collection. 

Remarks: This distinctive western Pacific 
species (Shikama, 1977, p. 1,5. pi. 2, figs. 10a, 10b) 
is characterized by the relatively small size of the 
body whorl, the slightly extended spire, the 
lengthy spines, and prominent webbing (figures 9, 
10). It was compared by Shikama (1977. p. 15) to 
several unrelated long-spined species: Chicoreus 
damicornis (Hedley, 1903), C. ojcicomis (Lamarck, 
1822), and Murex lonyiconiiii Dunker, 1864. 



SUBFA.MILYTv-phinae 
Genus Siphonocheluii Jousseame, 1880 
Type species: Tijphix areiiatiix [sic] Hinds. 1844 ( = 7*. ar- 
cuatiis Hinds, 1843), by original designation. 

Siphonochelus radwini n. sp. 

Figs. 20, -jl 

Description: Shell small for genus, attaining 5 
mm (holotype immature, lacking perhaps one 
body whorl), fusifomi; spire acute, of !'< bulbous 
nuclear whorls, followed by 3 weakly angulate 
ix)stnuclear whorls; suture impressed. Body whorl 
lai'ge. fusoid; aperture small, ovate with an entire 
and erect peristome. Anal sulcus apparently lack- 
ing, but with a moderately long anal tube, arising 
at the rounded, poorly defined margin of shoulder 



Vol.iKHD 



January 10, 1979 



THE NAUTILUS 




20 




FIGS. 20 and 21, Siphonochelas radwini n. sp.. Iwluttjpe. 
NMNH 323198 (drmdngs by Anthony D'Attilio); greatly 
enlarged (mt II ml. tize = 5.0 mm. In length). 



in each varical interspace, and more closely 
placed to the earlier of the two varices. Proximal 
portion of each tube on the body swollen and ax- 
ially depressed on the left side below the shoulder 
margin. A minor swelling produced on the lead- 
ing side of each tube, terminating as a fold at the 
margin of the shoulder. Distal portion of tubes 
generally short, slanted, and irregular in cross- 
section. Last tube largest, weakly bent to the 
right, and the only one remaining open. Body 
whorl with 4 varices: each varical margin with a 
slight axial thickening corresponding to a former 
outer apertural lip. With increasing whorl size, 
position of each tube slightly ahead (in the direc- 
tion of growth) of the corresponding tube on the 
preceeding whorl. Siphonal canal broad, moder- 
ately short, tapering, closed, bent to the right and 
dorsally recurved. Shell dull-white; aperture 
polished white. 

Mea.'^urements: Holotype (figure 20, 21), length 
5.0 mm, width 2.5 mm. 

Tijpe locoUty: Off Cabo Catoche, Yucatan, Mex- 
ico, dredged in 46 meters, USBF Sta. 2361. 
Material studied: Holotype NMNH 323198. 
Remarh: We have followed the genus-group 
concept of Radwin and D'Attilio (1976, pp. 198- 
200) in assigning this new species to Sipho- 
nochdm. the first record of a living represen- 
tative of this genus from the New World. Addi- 
tional living species of Siphnnochelus are 
recorded by these authors from the western 
Pacific and from off the Cape of Good Hope. It 
should be noted, however, that Radwin and D'At- 
tilio (1976) rejected the previous assignment by 
several authors of western Atlantic species to 
Siphonnchehis (e.g.: Keen, 1944; Gertman, 1969; 
and Bayer, 1971): see also Penna-Neme and Leme 
(1978) for their use of Siphoriochelus for an 
eastern American species. 

Although this taxon is based on a unique, ap- 
parently immature specimen, its distinctive 
morphology, together with its occurrence in the 
Western Hemisphere, has led us to describe it. 

LITERATURE CITED 

Bayer. F. M. 1971. Biological results of the Univereity of 
Miami Deep-Sea Expedition 79. New and unusual moUusks 
collected by R/V -John Elliot Pilhbury and RA^ Gerda in 
the tropical western Atlantic. Bnll. Mar. Sri. 21(l):lll-236. 
72 figs. 



10 THE NAUTILUS 



January 10. 1979 



Vol. 93(1) 



Bivona-Beraardi. A. IKfi. Caratteri di alcune specie de con- 

chiglie, estratti come sopra. F^fem Sci. Lett. Sicitia 1 16-24. 
Blainville, H. M. D. de. 1829. Fauna franpise ou histoire 

naturelle, gene'rale, et particuliere des animaux qui 

retrouve en France. Moilusques. Levraux, Paris 1-320. pis. 

Ml, 
Clench, W. .J., and 1. Pe'rez Farfante. 1945. The genus Murex 

in the western .■Mlantic.MH.s-oHiVi 1(17):1-,t6, pis. 1-28. 
Crosse. H. 1869. Diagnosis moiiuscorum novorum. Jmtrn. de 

Coiichyl. n-.-m-iW. 
De.shayes. G. P. 18.39. Nouvelles especes de moilusques. prove- 

nant des c3tes de la Californie, du Mexique. du Kamt- 

schatka et de la Nouvelle Zelande. d&rites par M. 

Deshayes. Rev. Zool. Soc. Qmerierenne. 2:.356-61. 
Dunker. W. 1864. Fiinf neue Mollusken. Malak. Bliitt. 

11:99-102. 
Gertman. R. 1969. Cenozoic Tj'phinae (Mollusca: Gastropoda) 

of the western Atlantic region. Txlaiie Stud. Ceol. and 

Meant. 7(4): 14.3-191, pis. 1-8. 
Habe. T. 1961. Caloured illmtratians of the shelh < if -Japan 

[vol. 2]. Hoikusha, Osaka. 183 p.. 66 pis. 
Habe. T.. and S. Kosuge. 1971. Pacific Shell News. Tokyo. 

Japan. (3):7. (Published on October 30, 1971). 
Hedley. C. 190.3. Scientific results of the trawling expedition 

of H. M. C. S. Thetis off the coast of New South Wales in 

Feb. and Mar., 1898, pt. 6. Mem. Australian Mus. 

4(l):.326-402, pis. 36-38. figs. 61-1 13. 
Hinds, R. B. 1843. On new species of shells collected by Sir 

Edward Belcher. C. B. Proc. Zool Soc. London, for 1843. 

11: 17-19 (July. 1843). 
1844. The zoology of the voyage of H. M. S. 

Sidphur. London. Mollusca, pt. 1, 1-^4, pis. 1-7 (July, 1844). 
Jousseaimie, F. 1880. Division methodique de la famille des 

Purpurides. Le Naturaliste,42:.3a5-336. 
Keen, A. M. 1944. Catalogue and revision of the gastropod 

subfamily Typhinae. Jour. Pcdeont. 18(l):.50-72. 20 figs. 



I^niarck. J. B. P. A. 1822. Hittoire naturelle des animaux 

.sfiH.s veiiebrex. Paris. 7, 232 pp. 
Melvill. J. C. and R. Standen. 1899. Report on the marine 

Mollusca obtained during the first expedition of Prof. A. C. 

Haddon to the Torres Straits in 1888-1889. Jour. Linn. Soc. 

London. 27:1.50-206. pis. 1, 2. 
190.3. Descriptions of 68 new Gastropoda from the 

Persian Gulf. Gulf of Oman and N. .Arabian Sea dredged by 

Mr. F. W. Townsend of the Indo-European Telegraph Svc. 

1901-190,3. .4«n.A/as.A'a/. Hist. 12:289-.324. pis. 20-23. 
Monterosato, T. A. di. 1890. Conchiglie della profundita del 

mare di Palermo. A^a<. Sicil. 9:140, 1.51, 157-66, 181-91. 
Penna-Neme, L., and J. L. Moreira Leme. 1978. Novas especies 

e novas ooorrencias de gastropodos marinhos na costa 

Brsisileira. Pap. Avidsos Zool, SSb Paulo 31(18):283-297, 33 

figs. 
Ponder, W. F. 1972, Notes on some Australian genera and 

species of the family Muricidae (Neogastropoda). Jour. 

Malac. Soc. Austral. 2(3):215-248. 
Radwin. G, E.. and A. D'Attilio. 1976. Murex Shells of the 

World, an illastrated guide to the Muricidae. Stanford 

Univ. Press. 284 p.. 32 pis.. 198 text figs. 
Shikama. T. 1977. Descriptions of new and noteworthy 

Giistropoda from western Pacific and Indian Oceans. Set. 

Reixiiis, Yokohoma Natl. Univ.. sect. 2. Biol, and Geol. Sci., 

no. 24:9-23. pis. 1-5. 2 figs. 
Sowerby, G. B. II. 1834. The conchological illustrations, Murex. 

London, pis. .58-67. 

1841. Ibid., pis. 187-189, and catalogue, p. 1-9 

Yokes, Emily H. 1975. Cenozoic Muricidae of the western 

Atlantic r^ion. Pt. 6, Aspella and Dermomurex. Tiilane 

Stud. Geol and Paleont. 11(3): 121-162, pis. 1-7. 
Wanner. J. and E. Hahn. 193.5 Miocane Mollusken aus der 

Liindschafe Rembang (Java). Zeitsch. Deutsch. Geol Gesell. 

Berlin 87(4):222-273, pis. 17-21. 



SCAPHELLA CONTOYENSIS, 
A NEW VOLUTID (GASTROPODA) FROM EAST MEXICO 



William K. Emerson 



and 



William E. Old. Jr. 



Department of Invertebrates 

American Museum of Natural History 

New York. N. Y. UX)24 

ABSTRACT 

Scaphella contoyensis, a new species from the Yucatan Channel, Mexico, is 
desciibed and compared urith related volutid species of the New World subfamily 
Scaphellinae. 



During the past decade, several examples of a 
large, thin-shelled volute have been obtained by 
shrimpers in depths ranging from about 70 to 180 



meters in the Yucatan Channel, mostly in the 
vicinity of Contoy Light, off Cabo Catoche, 
Yucatan, Mexico. These specimens are somewhat 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 11 



reminiscent of Australian species of Ericusa and 
Cymhiolista in size and coloration, but they lack 
the spinose ornamentation that characterizes the 
latter Indo-Pacific forms. 

Specimens of the new species were generously 
donated to us by Donna and Riley Black and 
Elsie Malone of Ft. Myers, Florida, and Dr. 
William J. Clench of Dorchester, Massachusetts. 
Gene Everson of Ft. Lauderdale, Florida, kindly 
lent a specimen from his collection and donated 
the soft parts. These specimens fonu the basis for 
the present report. Additional specimens, all 
taken by dredging in the Yucatan Channel, are 
preserved in the following private collections: 
Christine S. Goddard of Ft. Myers Beach, Florida, 
1 specimen, in 46 meters, March 1968. Barbara 
and Thomas McGinn of Cutoff, Louisiana, 8 
specimens (2 of which are now in the collection of 
the American Museum of Natural History), in 
132 to 183 meters, February 1970, (1 specimen), 
March, 1972 (6 specimens), 1975 (1 specimen); 
Elsie Malone of Ft. Myers, Florida, 1 specimen in 
90 meters, ex Carmel and Wassy Frank collection; 
Carmel and Wassy Frank, Ft. Myers, Florida, 2 
specimens (teste Elsie Malone); and Ernie 
Ryckman, of Key West, Florida, 1 specimen. We 
are grateful to these collectors for providing data 
and photographs of their specimens. 

Drs. Frederick M. Bayer and Joseph Rosewater 
of the National Museum of Natural History also 
contributed data, and the latter lent us the 
holot>T3ic specimen of Scaphella evelina Bayer. 
Our colleague, G. Robert Adlington, photographed 
the specimens illustrated in this paper. 

TAXONOMIC PLACEMENT 

Bayer (1971, pp. 200-221) succintly reviewed the 
pertinent literature pertaining to the classifica- 
tion of the western Atlantic species of Volutidae 
[q.v., Clench, 1946, 1953; Clench and Turner, 1964, 
1970; Olsson, 1965; Pilsbry and Olsson, 1953, 1954, 
and Weaver and duPont, 1970). We concur with 
Bayer's conclusion that the classification of the 
family is ". . . still a difficult matter," as the 
genus-group assignment of the Scaphella 
described herein proved to be perplexing because 
of conflicting data. We must, however, comment 
on Bayer's (1971, p. 195) placement of the genus 



Teramarhia Kuroda, 1931, in the family Tur- 
binellidae, based largely on shell characters in 
the absence to him of information on the radula. 
Anthony D'Attilio (in litt.) has pointed out to us 
that the radular characters of T. tlbiaefonnis 
Kuroda, 1931, the type species of Teramachia, as 
illustrated by Habe (1952, p. 132, fig. 12), are 
typically volutid. This genus is, therefore, 
referable to the subfamily Calliotectinae Pilsbry 
and Olsson, 1954, on the basis of radular and 
opercular morphology (v. et.. Weaver and duPont; 
1970, p. 177, fig. 41b, for an illustration of the 
operculum). 

In the most recent reviews of the subfamily 
Scaphellinae, Bayer (1971, pp. 209-216) and 
Weaver and duPont (1970, pp. 140-145) recog- 
nized the genus Scaphella as a polytypic taxon to 
include, in addition to the nominate subgenus, 
the subgenera: Qenchina. Pilsbry and Olsson, 
1953 (type species by original designation: Voliita 
dohrni Sowerby, 1903, = S. govMiana (Dall, 
1887), fide Abbott, 1974, p. 244) and Aurinia H. 
and A. Adams, 1853 (type species by original 
designation: Volutia dubia Broderip, 1827). The 
subgeneric units were separated by these authors 
largely on the basis of minor differences in the 
radular morphology, as defined by Pilsbry and 
Olsson (1954) in their "Systems of the Volutidae". 
According to Bayer (1971, p. 209, and fig. 63), the 
t.vpe species of Scaphella (sensu strkto), Voluta 
junonia Lamarck, 1804, has ". . .a single long, 
concave cusp and no small basal denticles."; S. 
(Clenchina) dohrni has "... a shorter, more 
pointed, concave cusp flanked by minute acces- 
sory cusps."; and S (Aurinia) dubia, together 
with the genus Volutifusus Conrad, 1863, has 
". . .a well -developed lateral cusp on each side of 
the main, central cusp." Bayer concluded that the 
simple Y-shaped teeth of S. junonia had resulted 
from progressive reduction of the side-denticles 
from the well-developed tricuspid teeth of Au- 
rinia and he suggested that these distinctions 
would be found to be of minor taxonomic sig- 
nificance, when more radular data became 
known. The radular morphology of the new spe- 
cies of Scaphella described herein serves to sup- 
port Bayer's thesis, because the teeth lack basal 
denticles (fig. 7), in contrast to the denticled 
teeth of S. evelina Bayer (1971, fig. 63), which we 



12 THE NAUTILUS 



January 10, 1979 



Vol.93 (1) 



believe tx) be the closest known relative of S! 
nint(iye))!iis, n. sp. (see remarks below). 

In addition to the supposed radular differences, 
Scaphella (sensu stricto) and Scaphella (Clen- 
china) have been distinpuished by trivial con- 
cholopical characters, including the possession by 
the latter of less-solid shells than those of S. 
junonki (Weaver and duPont, 1970, p. 140). The 
basic similarity of the shell morphology, together 
with the minor differences of the radular 
characters, however, suggests to us that the 
genus-group taxon Genchim is of questionable 
taxonomic value and our new species, together 
with S. eveiina, should be assigned to Scaphella 
(sensu stncto). 

Family Volutidae 

Subfamily Scaphellinae 

Genus Scaphella Swainson, 1832 

Type species: Valuta jmumia Lamarck. 1804, by subseciuent 
designation. Herrmannsen. 1848, p. 423. 

Scaphella contoyensis, n. sp. 

Figures 1 -7 

Description: Shell fusiform, large (attaining 
170+ mm in length), with 6 whorls. Protoconch 
large and .smooth, consisting of about 2 whorls. 
The first three post-nuclear whorls are thicker 
and more solid than the fragile body whorl, 
which is thin and inflated in mature individuals. 
The first 2 post-nuclear whorls sculptured with 
fine intersecting spiral and axial cords that give 
a weakly cancellate appearance to the surface 
(figure 5). Surface sculpture of the third post- 
nuclear whorl, especially posteriorly near the 
suture, is microscopically cancellate, but the 
sculpture is scarcely perceptible and the surface 
becomes macroscopically smooth on the body 
whorl. Spire short, not acutely angled; .suture 
well-defined, moderately impressed. Aperture 
elongate-elliptical; outer lip thin and the parietal 
wall thinly glazed. Anal sulcus narrow and con- 
stricted [wsteriorly; .si phonal canal broadly ex- 
tended. Columella slightly arched, with two plica- 
tions extending within the aperture. Periostra- 
cum tannish yellow and exceedingly thin. 

Color of nuclear whorls is uniformly tanni.sh 
brown; ground color of second and third po.st- 
nuclear whorls buff, overlaid with two spiral 



rows of irregular, elongated, chestnut-brown 
spots; ground color of third post-nuclear whorl 
and body whorl is a darker buff, with in- 
terspersed spiral bands of chestnut-browTi streaks, 
which are lighter than the earlier chestnut-brown 
spots. In mature specimens, the interior edge of 
the outer lip (figure 3) has a c-ontinuous band of 
dark brown and the aperture is glossy, tannish- 
yellow to apricot. 

Softpaiis: Length of foot, after preservation in 
alcohol, 78 mm; color-base whitish, with irregular 
dark markings that are preserved as black 
blotches (figure 6). Radula: Reduced to simple Y- 
shaped rachidian teeth lacking basal denticles 
(figure 7). An operculum is lacking. 

Measurements: Holotype 173 mm in length, 
67.3 mm in width; figured male paratype, length, 
70 mm in width (Everson collection); smallest 
specimen, immature, with three post-nuclear 
whorls, 56.5 mm in length (McGinn collection). 
Slender female specimen, 166 mm in length, 58.5 
mm in width (AMNH collection, ex McGinn and 
Clench). 

Tiipr liKvlity: Northwe.st of Contoy Light, 
Yucatan Channel, Mexico, dredged in 159 meters, 
September 1973, by Donna and Riley Black. 

Ti/pe specimens: Holotype, AMNH 187180 
(figures 1, 2, 5); paratype (figures 3, 4), north- 
west of Contoy Light, off Yucatan, Mexico, 
dredged in 73 meters, March 1978, Gene Everson 
collection. Paratype AMNH 182250, trawled off 
Punta Francisca, Yucatan, Mexico, in 183 meters, 
March 1972, ex McGinn collection. 

Kmnrn range: Yucatan Channel, off Cabo 
Catoche, in 73 to 160 meters, and off Punta Fran- 
cisca, in 183 meters, Yucatan, Mexico. 

Remarks: Scaphella contoyensis n. sp. appears 
to be most closely related to Scaphella rrrlina 
Bayer (1971, p. 213-216, figs. 63c, 64), a species 
described from off eastern Panama and Colombia, 
in depths of 137 to 641 meters. Bayer's taxon 
diffei's from the present species by the i>).s.session 
of an acute spire, in the development of much 
stronger cancellate .sculpture and a less fiaring 
outer lip, and by the pre.sence of a less distinctive 
and apparently inconsistent color pattern, as well 
as by the radular characters discussed abive. 



Vol. 93(1) 



January 10. 1979 



THE NAUTILUS 13 




FIGS. 1-6 Scaphella rontoyensis n. sp. 1, 2 hjUdtnu. AMXH lH7im. X'A: 1, Apetliiral vieu; note immature outer lip: 2, Dfrrsal 
i'iev. 3, 4, Paratifpe. Erersim collection. .Y' ?; 3, Apetiural i-ieic. note mature outer lip uith dark colored hand on interim- edge of 
the outer lip: 4, Dorsal vieu: 5, Enlargement of the apical region if the holotijpe. showing weak cancellate sculpture. X2. 6, Body 
oftheparatype specimen illustrated in figs. 2, 3, X'l: soft parts contracted hijpre.'^erration in alcohol and sans the liver 



The development of cancellate sculpture in this 
subfamily varies considerably among the species- 
group taxa and within some populations of these 
taxa. Of the extinct species that are most closely 
related to S junonia. the early post-nuclear 
whorls are weakly to moderately cancellate in S 
trenholmu (Tuomey and Holmes, 1856) from the 
Miocene and S. floridana (Heilprin, 1887) from 
the Pliocene. In the Miocene species, S. precursor- 
Gar Aner. 1948. however, post -nuclear whorls are 
strongly sculptured and a spiral row of regularly 



spaced nodules are found immediately below the 
sutures on the earlier whorls and the body 
whorl; the postsutural nodules become obsolete 
and replaced by wavy spiral cords and prominent 
axial ribs on the remainder of the body whorl in 
mature specimens. In the living species, weak to 
moderate cancellate sculpture occurs on the sec- 
ond and third pt«t-nuclear whorls of some in- 
dividuals of S junonia and S. gouldiana (especial- 
ly in the fornis named, S. robusta (Dall, 1889) and 
S mationae (Pilsbry and Olsson, 1953), some ex- 



11 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 




FIG. 7. The outline of a rachidian tooth o/ Scaphella con- 
toyensis n, sp.; greatly enlarged. 

amples of which possess nodular spiral bands on 
the earlier whorls.). All of the specimens of 5. 
contoyensis n. sp. and S. evelina that we have ex- 
amined have cancellate sculpture on the early 
whorls and near the suture on the body whorl. In 
the case of the former species, this sculpture is 
essentially microscopic, whereas in the latter 
species it is easily seen by the naked eye. 

LITERATURE CITED 

Abbott. R. T. 1974. Amerimn Seashetls. New York, 663 pp., 24 

pl.s.,(>1().5figs. 
Adams, H. and A. Adam.s. 18.5.3 [-1&58]. ne Genera of Recent 

Motlusca. 3 vols.. London. 
Bayer, F. M. 1971. Biological results of the University of 

Miami Deep-Sea Expeditions. 79. New and unusual 

mollusks collected by R/V John Elliott Pilhbtiry and RA' 

Ge)-(l(t in the tropical western Atlantic. Bull. Mar. 5>ci.. 

21(l):lll-236, 72 figs. ("March i.ssue". published on .June 16, 

1971; reprinted, in Studies in Tropical American Mollusks. 

pp. 111-236. Univ. Miami Pre.ss.on November 1. 1971). 
Broderip. VV. .J. 1827. Description of some new and rare shells. 

Zool. Journal. 3(9):81-85, pis. 3-4. 
Clench, W. ,1. 1946. The genera Bathyaurinia. Rehderia and 

Scaphelhi in the western Atlantic. .Jnhn.iinmi. 2(22):41-6(), 

pis. 24-31. 
1953. The genera Scaphetta and Aunniopsis in 

the western Atlantic. Ibid.. 2(.32):.376-380. pis. 186-187. 
Clench, W. ,1. and R. D. Turner. 19frl. The subfamilies 

Volutinae, Zidoninae. Odontocymbiolinae. and Calliotectinae 

in the western Atlantic. Jnhnsonia, 4(43): 129-180, pis. 

80-114. 



. 1970. The family Volutidae in the western Atlan- 
tic. Ibid., 4(48)::«9-.372. pis. 172-174. 
Conrad, T. A. 1863. Catalogue of the Miocene shells of the 

Atlantic Slope. Pmc. Amd. Nat. Sci. Philadelphia, for 1862, 

14:.559-.t82. 
Dall, W. H. 1887. [Correspondence], Conchologists' Exchange 

[The Nautilus], 2(1): 9- 10. 
. 1889 Report of the Mollusca. Part II. Gastropoda 

and Scaphopoda. Reports on the results of dredging ... in 

the Gulf of Mexico (1877-78) and in the Caribbean Sea 

(1879-80). by the U. S. Coast Survey steamer "Blake" . . . 

Bull. Miut. Comp. Zool.. Harvard Univ.. 18:1-492. pis. 10-40. 
Gardner. .J. 1948. Mollusca from the Miocene of Virginia and 

North Carolina, Pt. 2. Scaphopoda and Gastropoda. U. & 

Geol. Sun: Prof Paper 199-B, 179-310. 24-.38. 
Habe, T. 19.52. Pholadomyidae, Clavagellidae. Pandoridae, 

■luliidae . . . Rlmtrated Catalogue of Japanese Shells. No. 

18.PP. 121 -132, pi. 18, 28 figs. 
Heilprin, A. 1887. Explorations on the west coast of Florida 

and in the Okeechobee wilderness. TVan.s. Wagner Free /«.</. 

&•(■.. I:l-i:i4, 19 pis. 

Herrmannsen, A. N. 1848 [1846-18.52]. Indicis Generum 
Malacozoiman Primordia. Cassel, 2 vols, and supplement. 

Kuroda, T. 1931. Two new species of Volutacea. Ventts 

.3(l):4.5-49.3figs. 
Lamarck, J. B. P. A. 1804. Memoire sur deux especes nouvelles 

de volutes des Mers de la Nouvelle-Holland. Am. Mus. Nat. 

dWM. Nat. Paris, 5:154-160, pi. 12. 

Olsson, A. A. 1965. A review of the genus Voluta and the 
description of a new species. Bidl. Amer. Paleont., 
49(224):6.53-672, pis. 80-83. 

Pilsbry. H. A., and A. A. Olsson. 19.5.3. Materials for a revision 
of east coast and Floridian volutes. The Nautilus 67(1):1-13, 
pis. 1-3. 

1954. Systems of the Volutidae. Bull. Amer. 

Paleont.. 35(152):271-306, pis. 25-28. 

Sowerby, G. B., III. 1903. Descriptions of new species of Nassa, 
Purpura, Latirus, Voluta, Conns, Stomatella. and Spon- 
dylus. Jour. Malacology 10(3):73-77, pi. 5. 

Swainson. W. [1831-] 1832. Zoological Rlustrations. Ijondon. 

ser.2. 2(11-20). pis. 46-9L 
Tuomey. M. and F. S. Holmes. 18.56. Pleiocene [sic] fossils of 

South Carolina, containing descriptions and figures of the 

Polyporia, Echinodermata, and Mollusca. Charleston, South 

Carolina. 1.52 pp.. 30 pis. 

Weaver. C. S.. and .1. E. duPont. 1970. Living Volutes, a 
monograph of the Recent Volutidae of the world. Mong. Ser. 
no. 1, Delaware Mus. Nat. Hist., xv -I- 375 pp., 79 pis., 43 
figs., 13 maps. 



Vol. 93(1) January 10, 1979 THE NAUTILUS 15 

A BIOGRAPHY OF ANDREW GARRETT, EARLY NATURALIST OF POLYNESIA: PART V 

W. Stephen Thomas 

Director - Emeintus 

Rochester Museum and Science Center 

Rochester, New Yorl< 14610 



Andrew Garrett was an American explorer, 
naturalist and artist who specialized in 
malacology and ichthyology. He gathered and 
studied forms of many other invertebrates, such 
as corals and echinodenns, and made careful 
drawings of them. He also collected specimens of 
insects, birds, plants, and a few anthropological 
artifacts, some of which are doubtlessly resting 
anonymously in museums or private collections. 
He also described and drew watercolors of several 
dozen species of shells and several hundred fish, 
many of which are as yet unpublished. 

Garrett lived and worked in various areas of 
the Pacific Ocean from the Hawaiian Islands to 
Fiji, the Marshall Islands, the Gilberts, Samoa, 
Tonga, the Cook Islands and the Society group. 
From 1856 to the early 1870's, his most produc- 
tive years, he spent much of his time as a collec- 
tor for Professor Louis Agassiz of Hai-vard Col- 
lege and in the latter part of this period, from 
1873-5, served in the same capacity for the 
zoological and anthropological museum of the J. 
C. Godeffroy trading firm of Hamburg, Ger- 
many. In the last fifteen years of his life, while 
located permanently in French Polynesia, he ad- 
ded to his own vast collection of shells, part of 
which he occasionally sold and exchanged. He 
wrote twenty-one scientific papers which were 
published in journals in both America and 
Europe. One of the monuments of his zealous 
work were the 470 species of fishes which he 
gathered, described and drew in color for the im- 
portant text edited by Dr. Albert C. L. G. Gun- 
ther. The Godeffroy Museum published the book, 
the first two volumes of which appeared from 
1873 to 1875, and the final volume of which was 
issued in 1909, twenty years after Garrett's 



death. This production remained for forty years 
one of the most authoritative publications on 
fishes of Oceania.' 

Unfortunately the name of Andrew Garrett is 
virtually forgotten, except by a few experts. Much 
of Garrett's important pioneer efforts in the field 
of marine biology were published by other 
authors, so that due credit was not always given 
him. Only one brief obituary was printed 
simultaneously in several scientific journals in 
America and England a few months after his 
death. A short outline of some of his ac- 
complishments was included in the National 
Cyclopaedia of American Biography for the year 
1899 (vol. 2, p. 162), but not in succeeding editions 
or in similar compilations or in histories of 
science. For many years his name and accom- 
plishments were omitted from print. However, in 



* Part 2: Catalogue of Molluscan Species and Bibliograph.v of 
Andrew Garrett by William J. Clench will follow in the next 
issue of The Nautilus. Manuscripts submitted November It;. 
1977. 




FIG. 1. Andrew Garrett (1823-1887). Fhntngraph probably 
taken in Haivaii about 1863. Original in the Museum of Com- 
ixirative Zoology. Harvard College, A/ass. 



16 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



the last twenty -five years there have been several 
short articles about him, one a brief chapter in a 
historical treatise on early scientific collecting in 
the Pacific' A factor which may account for the 
eclipse of Garrett's reputation after his death was 
the nonexistence of diaries or personal papers. In 
the letters from him which do exist, he seldom 
mentions particulars of his private life. Further- 
more, his specimens and drawings are widely 
scattered throughout the world with no inventory 
of his scientific collections ever having been 
made. Because of his colorful life and amazing 
travels there were many stories and possibly 
apocryphal tales. According to one story, Garrett 
had a mistress established on each of the islands 
where he periodically visited who made scientific 
collections for him in his absence. Another story 
concerns a queen of a remote locality where he 
was staying who induced her subjects to seize a 
barrel of his collecting alcohol. He had intended 
it to last for a year of collecting but it was con- 
sumed in one evening's drunken orgy. There has 
been no way of substantiating these tales as they 
were passed down by word of mouth. Furthermore, 
owing to gaps in our information as to Garrett's 
whereabouts it is unlikely that a definitive 
biogj-aphy of him will ever be written. However, the 
present account is an attempt to present a resume' 
of the information that can be documented. 

Early Life 

This pioneer and largely self-trained naturalist 
was bjrn in Albany, N. Y., on April 9, 1823. He 
was the third son of fourteen children and spent 
part of his early youth near Middlebuiy. Ver- 
mont. His father, Francis Garrett, was a native of 
Canada; his mother, born Joanna Campanaux, 
was a native of Belgium, and of good education. 
She sp(jke several languages. After Andrew left 
home at the early age of eleven, his family moved 
to Albany, N. Y.^ 

Early in his life young Garrett showed 
evidence of both independence and scientific 
curiosity. When he was eight years old he left 
home without warning to visit a museum one 
hundred miles away, and, then, having successful- 
ly completed his mi.ssion, returned safely. When 
only eleven he was apprenticed to learn the trade 



of an iron molder. At sixteen he abandoned this 
vocation and went to sea as a sailor for a period 
of three years. During that time, according to his 
owTi account, he touched at "nearly all the West 
Indian Islands, the Cape Verde Islands, off the 
African coast, as well as the Azores and Brazil 
and several Southern States." Reminiscing on this 
exploit several years later, he wrote, "I now went 
to work at my trade again, spending my leisure 
time studying the plants and shells. Still, my love 
of seeing new countries was not in the least 
abated so I travelled and worked (1842-1846) in 
various parts of the Northern, Middle and 
Western States."* 

After these wanderings Andrew determined to 
go abroad again. Meanwhile, he had not neglected 
his interest in natural history, for it was during 
this time of roving that he lingered briefly in 
Boston, spending happy hours in the museum of 
the Boston Society of Natural History. "I 
wandered about the suburbs of the city with 
Bigelow's Flinri B(if;t(inic))sis in my hand, study- 
ing plants. Having travelled in 23 States of the 
Union, I concluded to go abroad again."* 

Pursuing his ambitions Andrew found himself 
on June 7, 1846, signed up as a crew member of a 
whaling vessel in New Bedford, Massachusetts. It 
was the bark Edward, bound for the Pacific' 
Somewhere in the early course of this voyage, 
Garrett shipped over to another whaler, the Mza 
L. B. Jenney, which had left Fairhaven, 
Massachusetts, on November 30, 1846. It was 
fi'om this vessel on May 22, 1847, that Garrett 
stepped ashore at the busy port of Honolulu. The 
place caught his fancy, and he wrote some years 
later that he was so much pleased with its ap- 
pearance that he made up his mind to settle 
there.' This, indeed, was the goal he achieved five 
years latei'. 

Within a day or two of Garrett's arrival, an 
American missionary, the Reverend S. C. Damon 
paid a visit to the Jenney. Damon was the editor 
of the weekly journal, The Friend, dedicated to 
the spread of religion among seafaring men. Used 
to boi.sterous sailors who passed through the 
Hawaiian Islands, the minister was charmed by 
the inquisitive young man who was an amateur 
scientist. Such a vivid impression did Garrett 



Vol. 93(1) 



January 10. 1979 



THE NAUTILUS 17 



make upon the older man that eleven years after- 
wards, Damon wrote; "We recollect to have ac- 
companied him to the forecastle, and beheld with 
delight the collection of shells which he had 
already made. In reply to the question, 'Why did 
you ship before the mast?' he answered, 'In order 
to study conchology.' "' 

That extended sea voyage marked a highlight 
in the life of the young sailor not only because of 
a variety of adventures but also the experiences 
he gained in e.xotic and faraway localities. These 
included the Marianas, the Bonins, the Ryukyu 
or Liu Chiu Islands, as well as China, the Philip- 
pines, and some Australian and East Indian 
ports. 

When Garrett returned with his vessel on May 
15, 1851, to its home port of Fairhaven, adjacent 
to New Bedford, he must have gained some 
satisfaction as the yield in sperm whale oil 
from this voyage amounted to '2,570 barrels. That 
was roughly the equivalent of $20,000. Although 
Garrett was only a foremast hand on a whaling 
ship his share must have been considered a pro- 
fitable return for the times. But even more im- 
portant to him were the twenty packing cases of 
shell specimens which he had assidiously col- 
lected during the long voyage. He himself men- 
tioned this success six years after the incident 
when he was corresponding with his Boston 
patron, James M. Barnard. The sailor-naturalist 
took pains to mention that the proprietor of a 
shell store on State Street in Boston had bought 
the shells as well as some of the skins of birds, 
specimens of fishes and Crustacea which he had 
collected." 

Ashore in Boston in the spring of 1851, he 
seemed uncertain of what his future held. He was 
twenty -eight and he had behind him a rather 
rough and wandering life. But he was also becom- 
ing more and more engaged in the study of 
natural history. The idea of sojourning some- 
where in the Pacific Ocean and perhaps spend- 
ing his life there must have been in his thoughts. 
Even six years before when his whaling ship had 
touched at Honolulu, he wrote he had been so 
pleased that, "I was determined to settle there"." 
During the next year or so after his return he 
travelled "through most of the States" as he ex- 



pressed it, perhaps working as an iron molder. 
Finally, he left California, touching briefly at Rio 
de Janeiro and from that port finally headed for 
the Sandwich Islands, then also known as the 
Kingdom of Hawaii. He arrived in Honolulu 
sometime in the spring of 1852, and shortly 
thereafter made his temjwrary abode on the 
larger island of Hawaii. He remained there, ex- 
cept for various collecting trips in othei' parts of 
the Pacific, until 1863. 

In the Hawaiian Islands 

Why Garrett selected Hilo to be his headquarters 
will probably never be known. Of course, it was one 
of the three Sandwich Island ports preferred by the 
captains of the whaling ships from the 1830's until 
the time of the Civil War, when the whaling in- 
dustry greatly diminished. 

In 1850 the total population of the five islands of 
the Kingdom of Hawaii was only 84,165 in contrast 
to the approximately 840,000 living there today. 
The number of foreigners was only 1,962, a little 
over 2%. These persons were missionaries, traders, 
plantation owners, and others, some of whom had 
married Hawaiians and occupied government 
jxjsitions. Others were members of the diplomatic 
corps. King Kamehameha III was in the twenty- 
seventh year of his reign.' 

Garrett was an ardent shell collector when he 
arrived in Hawaii in 1852 but he lacked scientific 
training. Doubtless, it was his association with a 
few skilled amateur naturalists which influenced 
his future career and raised the level of his in- 
terests above those of the mere collector. But, being 
somewhat quiet and shy he did not befriend these 
persf^ns at once. His acquaintance and friendship 
with the avocational scientists of the Islands seems 
to have come about gradually. 

Above all, it must have been the richness of 
nature in Hawaii which aroused and stimulated 
the spirit of inquii7. At first he seems to have been 
drifting along without any set purpose. We do not 
know whether or not he had some occupation or 
how he supported himself at this time. However, in 
the fall he received a letter from Dr. Wesley 
Newcomb, an American physician and naturalist 
who had come to the Islands for his health. 
Newmmb established a private medical practice 



18 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



and eventually became government Health Officer, 
devoting himself on the side t<^) his hobby of con- 
chology. His first scientific paper on land shells en- 
titled "New Achatinclla" was published by the 
New York Lyceum of Natural History in 1853. It is 
known that Garrett collected for Newcomb and 
within a year the doctor was proposing to name a 
new species of shell in honor of his friend, writing, 
"It would afford me much pleasure to embalm your 
name not your person, to have it associated with a 
fine, new species from Hawaii. When this is fixed, 
it descends through all coming time."' 

At this time in Honolulu there was considerable 
interest in collecting shells, both local specimens 
and those from foreign shores. The comings and 
goings of sea captains and sailors, traders and 
missionaries probably had stimulated this traffic. 
The great abundance of tree snails with their 
bright colors, gathered by the native Hawaiians, 
was another form of trade. There was even a shell 
store in Honolulu from about 1852 to 1858, main- 
tained by Dominique Frick, who had once been the 
French consular agent.' 

We know that Newcomb left for the United 
States in March, 1855, but we do not know much 
about Garrett's association with other naturalists, 
e.xcept that he was collecting and had access to a 
limited amount of literature and at the same time 
was teaching himself to draw and paint. It may 
have been due to loneliness but also due to his 
aspirations of becoming a professional collector 
that Garrett on January 29, 1855, wrote a letter to 
one of the most distinguished scientists of his day. 
He addressed it to Prof. Louis Agassiz who had 
recently arrived in the United States as lecturer at 
Harvard and who, anxious to build up a core of 
collectors throughout the world, had issued some 
printed literature soliciting contributions. Garrett 
included sample drawings of fishes and some in- 
vertebrates, explaining he would continue to make 
sketches... "so that in the event of your observing 
any new species, or such as you would like 
specimens of, you can inform me. . . I do not make 
any pretensions to a knowledge of Ichthyology. . . 
yet will endeavor to write a description of each." 
He continued that he would be glad to exchange 
specimens in any branches of natural history and 
desired in return either specimens of shells new to 



him or copies of such books as Storer's Fishes of 
Massachusetts or of Dr. Gould's books on shells.'" 
Although the financial resources of Harvard 
University were at a low ebb, a very fortunate 
arrangement was made through Agassiz's Boston 
friend, the merchant and shell collector, James M. 
Barnard. 

By September, 1856, almost seventeen months 
later, Garrett received a reply to his inquiry to 
Professor Agassiz. It was from Mr. Barnard, writ- 
ten on the professor's behalf, inviting young 
Garrett to become a zoological collector on a per- 
manent basis. Garrett replied that he was most 
happy to do so as he had no regular employment 
and was on the point of returning to the United 
States. In his letter of acceptance, he concluded to 
charge $400 per year which would cover all of his 
traveling expenses, food, hiring of assistants, his 
own salary and would further enable him to go on 
various ships to remote islands." 

The impetus furnished by Louis Agassiz for him 
to apply and improve his already self-acquired 
scientific techniques of observing, collecting and 
recording came to Garrett at what seems an ap- 
propriate time. On December 1, 1856, at Hilo he 
shipped aboard the whaleship, Lydia, whose master 
was John W. Leonard. Considering the territoiy 
covered in the voyage which included the Society 
Islands and some of the Marquesas Islands, the 
vessel was away from Hawaii for the surprisingly 
short span of three months. The voyage was highly 
.successful from the point of view of the variety and 
number of specimens gathered, but a tragic event 
came later. After the reshipment of the rollections 
to another vessel, the Joh)) Gilpin, the latter vessel 
was wrecked on its return to the United States in 
November, 1857, and its cargo lost, which included 
considerable but not all the material destined for 
Harvard.'^ It happened there were duplicates 
retained by Garrett and some of the fish pictures 
were already in the possession of Captain Leonard 
who eventually reached home safely. 

Recently, through the courtesy of Barbara John- 
son of Princeton, an interesting letter from 
Leonard to his wife, Lydia, has come to light. It 
provides confirmation that the American 
naturalist was making fish pictures specifically for 
Captain I^eonard. In part, I^onard s;iid, "Since I 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 19 



wrote last we have passed through several stirring 
adventures (new). We have been at Fannings 
Island, and Mitui, one of the lower archipelagos. 
And, also at the Island of Huehine [sic] where we 
have gathered a splendid lot of shells and fishes. 
We have a naturalist (Garrett) as Passenger with 
us which makes it very pleasant. And he is painting 
a fine lot of Fish for me and collecting a beautiful 
lot of shells. So I shall have a fine Colection [sic] 
when I get Home."" Of course, the principal 
benefactor was Harvard College and its museum of 
natural history. Later, most of this material was 
described and pictured in the publication of the 
Godeffroy Museum of Hamburg. 

We have in this statement Leonard's 
corroboration of the fact that part of this was the 
same collection of watercolor drawings, all drawn 
by Garrett, which survived in the family of John 
Leonard's descendants. They are now the property 
of the author of this article. A further item of in- 
terest is that the Leonard set contains a Garrett 
picture of a beautiful wrasse fish of the family 
Labridae which the artist -scientist named Julis 
leonardianum undoubtedly in honor of his whaler 
friend. 

A few months after Garrett returned from his 
voyage to Hawaii, he received a four-page letter in 
the handwriting of Professor Agassiz, addressed to 
John M. Barnard but intended for the naturalist- 
employee. It has significance, for it served as a 
guide for proper collecting and scientific ob- 
servation. A total of three such letters from Agassiz 
composed for Garrett's benefit still exist and are 
preserved in the library of the Bishop Museum in 
Honolulu. The first one, dated August 28, 1857, ex- 
plains: 

"The principal merit of collections of objects of 
nature is not desired in our days from the ac- 
cidental circumstances that they may contain new 
species but from the opportunity they afford of 
elucidating natural laws. The collector ought, 
therefore to have his attention constantly turned to 
this important end and must on that account 
collect in a particular way. . .'" 

He went on to e.xplain that large quantities of 
specimens of one species in all sizes should be ob- 
tained as they all afford the means of ascertaining 
the range of different species. He added that the 



slightest difference between specimens of adjoining 
localities should be taken into account. Even in the 
case of adjoining islands "or opposite shores of the 
same island specimens must be collected of 
everything. . . It is thus ascertained that the dif- 
ferent groups of Islands of the Pacific may be 
inhabited by distinct representatives but identity 
nuist be made out by direct comparison and can 
neither be assumed or denied before hand". 

Meanwhile, the instructions Garrett had re- 
ceived for collecting and his own zeal compelled 
him to adopt and use more precise methods. 
Through a letter to Barnard, written after the trip 
on the Lydia. he reported on his field collecting. He 
explained that he made it a point to gather those 
specimens which did not often occur. "When 
searching along the coast I have to take pencil and 
paper, an assortment of small jars, boxes and 
calabashes which my native boys carry. And when I 
find anything I which to preserve I first note the 
depth of water, kind of bottom, its mode of 
locomotion and colors while alive. And I find it 
necessary to preserve them in water while carrying 
them about so that their delicate parts will remain 
perfect until I can place them in alcohol." He said 
that he found it essential to make rough sketches of 
many objects in order to give a clear idea of their 
markings. He, also, added that he had his own 
catalogue of the crustaceans in which he recorded 
everything relative to each species which he 
found.'* It so happened that at the time Garrett 
mentioned his misgivings as a scientific field 
worker. Professor Agassiz had time to examine 
some of the young worker's drawings. In an un- 
dated letter to J. M. Barnard, probably written in 
the fall of 1857, he said "I have been much pleased 
with the drawings as well as the descriptions of Mr. 
Garrett. They will be invaluable material to clear 
up the Natural History of the Pacific Ocean but I 
would warn him not to be hasty in publishing 
them."" 

Relationship with 
William Harper Pease 

William Harper Pease (1824-1871), surveyor 
and conchologist, reached Hawaii when he was 
twenty-five years old. He had travelled in Mexico 
with General Scott's army and had made extensive 



20 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



collections there of birds, insects and other fauna 
for the Academy of Natural Sciences of Philadel- 
phia. Even at that early age, he had already pub- 
lished the first of his scientific papers which 
totalled 82 articles by the time of his death. Pease 
cho.se to be in Hawaii for reasons of health, reach- 
ing there in 1849 and residing in Honolulu until his 
demise in 1871. In a short time he became an im- 
portant man with interests enabling him to travel 
through the islands. He worked as a land surveyor, 
and held the position of Assessor of the City of 
Honolulu as well as being Commissioner of Water 
Rights. But, preeminently he was a scientist. 
Like Garrett he was a self-taught naturalist but by 
the time they met. Pease had acquired the dis- 
ciplines of scientific research and was an inveterate 
collector. Pease helped Garrett not only by engag- 
ing him as his principal collector but allowing his 
friend to use his conchological and scientific books, 
instructing him in method of research and in other 
ways. It is very fortunate that there was such a 
person available to Garrett for his guidance and 
stimulation, and as the two first met in 1857, in a 
sense Pease took the place of Newcomb who left the 
Islands in 18.56, and had formerly been the young 
collector's friend and mentor. 

For six yeai"s despite the various absences of 
Garrett on collecting trips, they saw each other 
fairly frequently. After the summer of 1863, 
Garrett left Hawaii never to return before Pease's 
death in 1871. but they kept up a faithful 
correspondence. A group of letters from Pease to 
Gari'ett written during the whole period of their 
fiiendship (1857-1871) sun-ives in Honolulu's 
Bishop Museum. Excerj^ts from them are given in 
the series of articles by Karl W. Green published in 
I960." and others were quoted in the biography of 
Pease by Dr. E. Allison Kay.' The relations of these 
two men was friendly, although Pease took almost 
a paternalistic attitude toward Garrett. There was 
a difficult side for Garrett. It is true that, in a 
sense, he was an employee of the other man, but in 
some ways Pease seems to have taken advantage of 
Garrett's abilities and efforts. The latter worked 
hard and laboriously. He collected amid the most 
trying and dangerous conditions. He scrupulously 
described and drew pictures of many of the 
specimens gathered, particularly the fishes. In the 



case of fishes and shells he suggested the scientific 
names. But despite all this, he lived in the shadow 
of Pease while the more articulate writer and more 
assertive man earned the glory. 

Collecting in the Kingsmill Islands 

Was it restlessness or a desire to form collections 
ft-om le.sser known areas that goaded Garrett to 
make so many scientific forays? We sense that the 
business arrangement with the museum at Har- 
vard as well as the enthusiasm of both Professor 
Louis Agassiz and the Boston businessman James 
M. Barnard, must have been the stimulants to these 
persistent travels. 

Hawaii was a focal point from which trading 
schooners and whaling ships, served as a means of 
transportation. One of the latter was the brig, Mar- 
ni)i(] Star, operated by the Board of Missions to con- 
vey American missionaries and their trained 
Hawaiian assistants to the various, far-flung island 
stations." These mission voyages were financed by 
sums of money raised, largely by New England 
school children. Garrett explained that he had 
made reasonable arrangements as a passanger 
aboard the Moi-ning Star paying $1.50 per day 
while he stayed on board, with an additional charge 
for his package of specimens. A plan developed so 
that he could sail directly to one of the islands and 
stay there collecting for three months." 

Our conchologist carried complete provisions as 
well as articles of trade to last him at least four 
months. The materials included cutlery, edge tools, 
beads, calico cloth and even 400 board feet of lum- 
ber with which to build wooden boxes for the 
return of his specimens. The brig, Morning Star, 
left Hawaii on August 11, 1859, but due to adverse 
winds and currents took longer for the trip to the 
South Pacific than would ordinarily be the case. 
Finally, after a voyage of three weeks from 
Honolulu, the two-masted vessel reached its 
destination on September 9th. This was Apiang, 
one of the northern islands of what are now known 
as the Gilberts in Micronesia. It must have been a 
strange, remote place, being flat and palm-covered 
coral rock. It was about fifteen miles square and 
had a total of not over 300 to 400 inhabitants, living 
in small, scattered villages. While the Rev. and 
Mrs. Hiram Bingham, who ran the mission, lived 



Vol. 93(1) 



January lU, 1979 



THE NAUTILUS 21 



near their thatched church a scant distance away, 
Garrett established himself in a rather flimsy, 
borrowed dwelling. With the limited help of his 
servant Temawa, the naturalist busied himself in 
making e.xtensive collections. To do this he daily 
waded for long hours over the inner and outer plat- 
forms of the nearby lagoons. He also exchanged 
small bits of his trade goods for selected specimens 
of fish, shells, echinoderms, and other forms of 
aquatic life. Several dozen natives crowded around 
him almost every hour of the day, causing him end- 
less misery. This slowed down his work of 
preparing specimens, making drawings and jotting 
down notes. Their repeated attempts to steal his 
belongings made him worn,' that they might seize 
and drink the precious preserving alcohol, so that 
he frequently worked into the late hours of the 
night when his unwelrome guests were not around. 
After some days of deceiving the natives about the 
alcohol, they detected its smell. They would have 
taken it from him had he not convinced them that 
it was poisonous type of substance. Another 
nuisance he had to bear were visits by inhabitants 
of other islands. All of them demanded to see and 
handle what they called his "wonders". These were 
a mechanical music box, a magnifier with mirror, 
and the "plates" or pictures of natural history sub- 
jects which he had brought with him or had done on 
the spot. Although his companions demanded that 
he buy all their zoological specimens they brought 
to him in large quantities, he found it judicious to 
acquire only a few representative ones from each 
lot so as not to discourage the vendors from con- 
tinuing to collect for him. Lacking a knowledge of 
the language, he was compelled to use pantomime 
combined with mixed words of Hawaiian and 
English, but seemed to succeed fairly well in com- 
municating. Unfortunately, at frequent intervals 
he was ill with fever or other complaints and when 
attempting to rest, found: "a pair of black eyes 
glistening at every crevice in sides of the house." 
Sometimes, due to the crowds of noisy visitors, for- 
ty or fifty in a group, he had to close up his house 
and take long walks to get away from the tumult." 

From time to time the busy collector had some 
contact with the ruler. King Tekaiia. This person 
did not seem to be a real monarch. Garrett 
described him as a large, corpulent man whose only 



clothing was a rough mat of leaves wrapped around 
his loins. He lacked the respect of his subjects who 
seemed to ignore his authority. When one day 
several unfamiliar natives arrived from the nearby 
Island of Maraki, Garrett noticed that they were 
"bringing with them several Kanaka heads. They 
stated that there had been a battle. . . and the heads 
were those of some of their friends who had been 
slain and they had cut them offf and fled to prevent 
them (the heads) from falling into the hands of the 
enemy." One detects a note of reprovement in our 
traveler's remarks on his observations of the 
Micronesian Christian converts. They often dozed 
during the sermons of the missionaries or plucked 
and ate the lice from each other's heads while at- 
tending church. He was further shocked when one 
day in passing the council house he was overcome 
by the stench from a putrid corpse. It was the body 
of an elderly and venerated chief whose funeral ser- 
vices extended over several days. 

Despite the hard times and vicissitudes which 
the naturalist had to endure, one realizes from his 
journal how enthusiastic and excited he became 
when he encountered new species of shells and fish. 
On its return from Apiang with Garrett and his 
booty aboard, his ship stopped at Ebon Island 
where he acquired additional specimens. When he 
arrived back in Hawaii on January 11. 1860, he 
must have had considerable satisfaction in the suc- 
cess of the expedition. A record of the importance 
of the venture is also incorporated in the official 
report of the Harvard Museum quoting Agassiz on 
the acquisitions from the Pacific Ocean, which 
stated, "the total number of specimens of fishes 
amounts to five thousand, comprising 1.000 dif- 
ferent species, the most important of which are 
from the Kingsmill and Society Islands, collected 
by Mr. Garrett"^" Despite this account it is quite 
likely there was an error in the report as the collec- 
tions noted probably included shells and other 
organisms in addition to fishes. 

Second Visit to the Society Islands 

It is unfortunate that there is such scant in- 
formation about Garrett's second visit to the 
Society Islands which took place from 1860 to 1863. 
The Society Islands offered ample opportunities for 
new discoveries, despite the collections of Captain 



22 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



James Cook's associates, Lesson, Hugh Cuming, 
and otliers. Commenting on the early work of these 
scientists, Garrett, writing some twenty years later 
in his own research article, remarked "During the 
years 1860-1863 I made a much more thorough ex- 
ploration (of land shells) than any of my 
predecessors, and by searching in nearly every 
valley of the group, discovered 50 new species. . ."^' 
He left Hawaii for Tahiti and the other islands in 
May, 1860." The manner of life of the natives there 
had probably not changed appreciably since his 
visit of three years previously when he observed, ". . 
conditions being there the same as at the Sandwich 
(Hawaiian) islands in the form of indolence, 
drunkeness, and the most loathsome diseases which 
he felt were rapidly decimating the population. I 
cannot perceive as they have improved an iota in 
there moral or physical condition notwithstanding 
40 years of missionary labor and intercourse with 
foreigners."" 

More importantly, he wrote of the marked 
similarity in the marine fauna in French Pol>Tiesia 
in comparison with that in the Sandwich Islands. 
Though the natives of each island group spoke a dif- 
ferent language, they used the same name for the 
same objects common to both areas. He noted that 
residents of Boston, New York and Baltimore had 
two or three names for the same natural species. 
Still he found natives living 2,000 miles away from 
one another speaking almost a different tongue but 
using the same name for the same species of fish. 
"All Polynesian Islanders have with very few ex- 
ceptions a distinct name for ever>' kind of animal, 
plant and mineral, no matter how small and ob- 
scure the object is." He concluded by saying "They 
as a mass have a better knowledge of the natural 
productions of the islands than the mass of people 
in the United States"." 

Although we have so little information about 
Garrett on this particular Society Island sojourn, 
we do find a reflection of his interests in the letters 
Pease wrote him and which he so carefully kept. On 
September 2, 1860, Pease wrote proposing their 
collaboration on a series of popular natural history 
publications which would contain lithographs of 
the watercolor drawings as well as printed descrip- 
tions of the more common fishes, shells and plants. 
"My opinion is the most effectual mode is to 



publish a small pamphlet in numbers, similar to 
those of Professor Adams, 'Contributions to Con- 
cholog>''. I think I shall issue one before you 
return." Pease went on to explain that the 
publication would contain "your descriptions of 
fishes and a portion of the descriptions of shells I 
have forwarded to Cumings."" It is quite likely 
that a series of 30 handwritten sheets of descrip- 
tions of fishes and shells of both Hawaii and the 
Society Islands in Garrett's handwriting with bor- 
ders drawn around them, each with a watercolor 
drawing, are part of the group previously men- 
tioned as now owned by the author were intended 
for the pamphlet. Unfortunately, the projected 
publication never appeared as far as is known. 



In the Central Pacific (1863-69) 

Apparently Garrett returned from his Society 
Island explorations about July, 1863. The months 
that followed were crucial ones as he decided to 
abandon his base in Hawaii and go off on even more 
extensive voyages. In welcoming him back to 
Honolulu, the Rev. Samuel C. Damon, reporting en- 
thusiastically of the naturalist's accomplishments, 
wrote ". . . he has visited every island and every 
valley and reef of every island, collecting specimens 
of shells, fishes and every variety of animal and in- 
sect. The extent of his collections may be indicated 
by the fact he has used three hundred gallons of 
alcohol in preserving the specimens. He has col- 
lected 400 different species of fishes. Each one of 
these is beautifully painted from life. Some of his 
drawings which we examined are executed with 
great skill and taste. The number of these 
specimens which were forwarded from the Society 
Islands would not fall below ten thousand. "^^ 

With his long journey behind him and with his 
collections shipped away, he had to put off the blan- 
dishments of his friend Pease. The latter was in- 
sisting that he remain and help with his projected 
commitments for publication. In fact. Pease at this 
time was writing several papers on land shells 
probably based in part on Garrett's collections. 
Eight papers appeared, chiefly on this topic, with 
Pease's name attached in the Proceedings of the 
Zoological Society of London between 1864 and 
1865.' 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 23 



Garrett, making preparations for his next ex- 
tended voyage, received a letter dated October from 
his San Francisco agent, Sam Hubbard. He had 
purchased for him a supply of alcohol, a music box 
with which to entertain the natives, a magnetic 
machine (which may have been a surveying instru- 
ment), and a series of other articles. The most 
expensive item was a complete wet plate photo- 
graphic apparatus which included a camera, plates 
and chemicals. It cost $376.76, an enormous sum, 
considering that Garrett's yearly salary was only 
$400. 

Another important activity for Garrett in his 
1863 stay in Hawaii was identifying both shells 
and fishes for the California Academy of Sciences. 
That institution had made him a corresponding 
member in 1856 and its Proceedirujs in 1857 had 
carried his article on marine shells, probably his 
first scientific contribution to be printed.^ That 
same organization, hearing of his new expedition, 
sent him twenty gallons of preserving alcohol 
which they said was to be used "according to your 
best judgment, taking sufficient of it to reimburse 
yourself."^ 

Meanwhile, in August, Damon, in the same letter 
referred to, outlined the extensive South Sea 
Islands voyage the conchologist was planning. It 
would include the Marquesas Islands, the Naviga- 
tors (Samoa), Friendly (Cook) and the Fiji Island 
groups. This would be a period of no less than five 
or six years which he would devote to new ex- 
plorations. Damon added, ". . .he is perfecting him- 
self in the photographic art, as he will go prepared 
to take views of natural scenery, animals and the 
inhabitants of those remote regions. Hereafter, his 
researches will embrace a wider range than they 
have hitherto done." 

Late in 1863 Garrett got off but we have only a 
vague knowledge of his specific locations in the 
next six years. He chose for his collecting grounds 
two main areas 2,000 miles and more south of his 
former haunts in the Hawaiian Islands. These 
were, first, the Tuamotu Islands, a large ar- 
chipelago, stretching from 140° to 150° West 
Latitude and situated east of the Society Islands. 
He seems to have been there for most of 1864 and 
1865 but we have no records of the precise places of 
his collecting. For the second part of his travels, he 



was in the Cook Islands, Western Samoa and, then 
for a good part of 1867 to 1869 he moved about the 
Cook Islands. 

Garrett was not only doing his usual collecting 
but was also taking photographs of the native 
people. We have already noted his purchase of a 
camera and the necessary equipment. On Januar>' 
20, 1864, not long after his departure from the 
Hawaiian Islands, Pease wrote to him ". . . Not a 
day passes without my dreaming of your fortune 
and success. I have imagined the missionaries 
might decide that your photographs were a useless 
article of furniture and discourage the natives from 
patronizing you, and then again I think I see you 
surrounded by a crowd of natives, dancing and 
shouting with the pictures. I shall be anxious to 
receive your first letter."" 

During the period 1863 to 1866, according to a 
recent writer, Pease continued to sponsor Garrett's 
trips at least in part and continued to act as his 
agent in Honolulu. Garrett sent Pease descriptions 
of his living specimens and drawings of shells and 
nudibranchs for inclusion in the numerous papers 
Pease was writing.' 

It cannot be accurately determined when Garrett 
ceased his activities on behalf of Harvard's musuem 
but it was sometime around 1863. Agassiz was 
having financial troubles at this time. Another 
factor could have been unfavorable circumstances 
brought on by the Civil War or other reasons which 
might have terminated James M. Barnard's annual 
payment of his salary. Certainly, the slacking off of 
American vessels engaged in the whaling industry 
all over the world may have been a contributing 
cause. Some of these vessels had been acquired by 
the Federal Government to be taken south and 
sunk to block up shipping in southern coastal ports, 
while others which were already at sea at the out- 
break of hostilities were captured or destroyed by 
the Confederate Navy. 

Garrett and the Godeffroy Museum 

These circumstances may well have helped bring 
about Garrett's affiliation with another 
organization. Ever since the early 19th century an 
important shipping and trading company of Ham- 
burg had operated vessels between Germany and 
South America's west coast. This was the firm of J. 



24 THE NAUTILUS 



Januao' 10. 1979 



Vol. 93(1) 



C. Godeffroy and Son, which after having suc- 
ces-sfully managed a fleet of cargo-carrying 
passenger ships to South America, Australia and 
California, found its business cut off after 1855. In 
that year one of its representatives, August Un- 
shelm, had been following orders seeking out 
business possibilities of trade for native products in 
such Pacific islands as the Carolines, the navigators 
(Samoa), the Friendly (Cook Islands) and the Fiji 
Islands. As a permanent headquarters and trading 
station for the whole area the firm purchased land 
at Apia, Samoa. For the next twelve years this 
grew into an impressive establishment with its own 
plantations of coconuts and cotton and a trading 
center serving several large clusters of remote 
islands. By 1864, a new Godeffroy employee, young 
Theodore Weber, took over as head of the business 
at Apia. He acquired more land and directed the 
production of copra which after its arrival in 
Europe was processed into candles and soap.^ 

Meanwhile, back in Hamburg, Johann Caesar 
Godeffroy, head of the firm, had a museum to house 
exhibits of rare material of the Pacific Islands in 
the fields of anthropology and zoology. He had 
hired a young Swiss zoologist, Dr. Edward Graeffe, 
to set up and display the collections which were 
being supplied by the captains of his twenty dif- 
ferent vessels then travelling back and forth bet- 
ween Hamburg and Oceania. They had special in- 
structions to secure natural history specimens and 
native artifacts. A year later, J. D. E. Schmelz, a 
qualified scientist, became custodian when Godef- 
froy sent Dr. Graeffe out to Samoa and Tahiti on a 
ten year assignment as collector for the new in- 
stitution. Simultaneously, the Musuem sent a small 



band of collector-scientists into the field. Garrett 
became one of these about two years later." 

By 1866 Garrett was established in Samoa and 
busy collecting on the Islands of Upolo and Savaii. 
His name had been known previously in Hamburg, 
as some of the shells he gathered were sold to the 
Hamburg government museum in 1862. About this 
time at Apia he came into the good graces of the 
Godeffroy representative, Weber, and in 1866 the 
American had obtained passage on the company's 
ship the Alfred which transported him to the Fijis. 
The agent reported this in a letter to his employer 
sent from Samoa August 17, 1866, requesting that 
Garrett be permanently engaged. Godeffroy ap- 
proved this recommendation and authorized 
Garrett to gather zoological specimens. Godeffroy 
promised to send the needed supplies for collecting 
and preserving. Garrett was to receive five hundred 
Chilean pesos for the first year, as well as free 
passage in the company ships and to be treated 
"always in the kindest way possible." In return for 
the payment and ship accommodations, the 
scientist was to provide a selection of his specimens 
for the company museum." 

It is particularly unfortunate that no detailed 
account of Garrett's activities in the Fiji Islands 
survives. Because of unstable political conditions of 
the country and the presence of savage cannibals he 
worked under extremely difficult conditions. Un- 
doubtedly, he was befriended by a few American 
and English missionaries. The kingdom had for 
several years carried a heavy financial debt to the 
United States incurred when the home of the 
American consul had been destroyed by a mob. Fiji 
had even sought to be taken over as a protectorate 



^/t^i /K 




■vy -cr-. 



A^ .^nz: fi-c^, M S. S^:^x^^ ^ J^J.^^ ^^-^^ — ^ 









FIG. 2. A sample of Andrew Garrett's handirritiny and signature fivni an ISX? letter irritten 
Hauhine Island. Society Islands t(i W. I). Hartninn of West Chester. Pa Oriyinai in the Smithsonian 
Institution. 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 25 



first by Great Britain and then by the American 
government but both offers had been refused. 
Finally, a Confederacy of Independent Kingdoms 
had been established in 1865." In 1868, when 
Garrett was there, a Polynesian Company had been 
formed to pay U. S. claims against King Cakobau in 
exchange for concessions. Looking back on his three 
year experience in that amazing cluster of 8(W lit- 
tle-explored islands, Garrett wrote in a letter nine 
years later ". . . in the Viti (Fiji) group I had several 
narrow escapes both from the natives and from 
drowning. They killed several whites, including a 
Missionary while I was there. The latter, together 
with several native teachers, were served up at one 
of their cannibal feasts. Shortly after I left the 
group there were a number of white residents 
killed by the savages, showing what risks the shell 
collector experiences when searching these 
regions."^' 

However, there is proof of Garrett's success in his 
collecting activities in the Fiji Islands. The sales 
catalogue of the Museum Godeffroy notes: "In 
regard to further research we advise that Andrew 
Garrett, well-known through his collection for 
Professor Agassiz and the fact that he has made the 
South Sea Islands his main task, has for some time 
extended his efforts on our behalf. The first ship- 
ment consisting mostly of animals of the Viti 
Islands has just arrived here. It consists of many 
interesting species such as amphibians, fish, 
crustaceans and a few polyps, worms as well as in- 
sects."^" 

But despite there somewhat pleasing results, a 
real tragedy occurred when a large portion of his 
final collections were destroyed in a shipwreck. 
Writing over two years later from Tahiti Garrett 
described his loss: ". . . When taking my departure 
after two years hard work I suffered a shipwreck 
and lost all my books on conchology, all my dried 
plants, Insects, Bird Skins, part of my Shells, Notes 
and Drawings and a series of Portraits of Natives 
which I had photographed. Fortunately, most of my 
shells had been shipped to Samoa in another 
vessel." He concluded by saying that from what he 
had saved from the wreck and what he had pre- 
viously shipped to Samoa, I find about 1500 
species of Viti (Fiji) shells and probably lost one or 
two hundred more.^' 



Last Years on Huahine (1870-1887) 

After 1870 Garret spent his remaining years in 
the Society Islands. He had established a home 
there, having made several stops on previous 
voyages. One should not be surprised that he chose 
the attractive island of Huahine, ninety miles nor- 
thwest of Tahiti, as his permanent home. It is a 
volcanic island of approximately ten square miles 
in area with twin mountain peaks, one of them 
rising over 2300 feet above the sea. His own descrip- 
tion, written after his first encounter early in 1858 
while a passenger aboard Captain John Leonard's 
whaleship. Lydia, says "The Island, in fact, consists 
of several islets which are separated by narrow 
channels. They present a bold and mountainous 
aspect, and are clothed in the most luxurious ver- 
dure from the water's edge to the summits. . . A 
short distance back there arises an amphitheatre of 
hills and mountains which are covered either with 
tall, rank grass or dense dark forests, and, the 
whole coast consists of a dense mass of fruit and 
splendid flowering trees, all combining to form one 
of the most delightful tropical scenes I ever wit- 
nessed."* 

Although we find some evidence that he 
travelled (probably by small sailing canoe) among 
the nearby islands of Raiatea and Moorea, and may 
have made occasional business trips for mail and 
supplies to Papeete, the capital and chief seaport, 
he had much to occupy him at home. He was busy 
making up selected sets of his duplicate shells and 
either selling or exchanging them with collectors in 
Australia, England, France and the United States. 
This work which involved comparison of shell iden- 
tifications led to extensive correspondence with 
both amateur and professional conchologists in- 
cluding R. E. C. Stearns of San Francisco, Berlin H. 
Wright of Penn Yan, New York, Rev. E. R. Beadle 
and George W. Tryon of Philadelphia, and various 
others. He maintained a steady correspondence 
with Dr. W. D. Hartmen of West Chester, Pen- 
nsylvania, and some of these letters from Garrett to 
the latter individual from 1874 to 1887 survive in 
the Carnegie Museum, Pittsburgh, Pa. In the mid- 
dle seventies and early eighties a total of eighteen 
of Garrett's Scientific papers were published in the 
Journal of the Academy of Natural Sciences of 



26 THE NAUTILUS 



January 10. 1979 



Vol. 93 (1) 



Philadelphia, the Journal de Conchyliolo(jie in 
Paris, and other scientific periodicals. 

During the first two years on Huahine 
(1870-1872) he must have devoted ojnsiderable 
time and energy to finishing and perfecting the 
descriptions of the collected specimens and the 
watercolor drawings of 476 different species of 
fishes from Hawaii, the Society Islands and the 
Fijis. Johann Caesar Godeffroy received this 
material in 1872 and thought so highly of it that he 
had the project edited and prepared by the 
celebrated ichythyologist of the British Museum, 
Dr. Albert C. L. Gunther. These compri.sed volumes 
1 and 2 of the prodigicjus work, "Andrew Garrett's 
Fische der Sundsee", published in Hamburg as part 
of the JounwJ of the Museum Godeffroy. Un- 
fortunately, the dissolution of the business of J. C. 
Godeffroy and Son in 1879 delayed further 
publication. But the final volume. No. 3 was issued 
in 1909. This work remained the ultimate authority 
on the fishes of the Pacific Ocean for almost forty 
years.^^ 

Little has come to light of Garrett's private life 
but we know he was legally married to a woman 
named Otari. One account states she was a 
Samoan^ and another informant, Alvin Seale, 
wrote after a visit to Garrett's home at Huahine on 
January 1, 1903 that Garrett's wife was the 
daughter of a high chief of the Island. It is not 
knovm whether or not they had any children, 
although the author made investigations of records 
on this topic on his two visits to Huahine and 
Tahiti in 1961 and 1974. He did find the site of 
Garrett's dwelling which was a short distance from 
the village of Fare. Mr. Seale describes it as "a neat 
little frame house, very comfortable and situated in 
a nice garden". It was on the edge of a bay and in 
sight of the ocean.'' 

In 1878 Garrett contemplated going to New 
Caledonia where he had a friend, (probably 
Rossiter] and also to the Solomon Islands. Instead 
he wrote Dr. Hartman of reports he had received of 
massacres of the whites by natives. ". . . Not having 
the slightest ambition to become a martyr in the 
name of Science, I think it will be the wisest course 
to postpone my visit to those savage islands."'* 

Fortunately this remarkable man did not suffer 
the kind of death he had feared in the far off can- 



nibal islands but in a sense his passing was no less 
li-agic as he died of a lingering case of cancer. On 
June 25, 1887 he wrote his friend Hartman in 
distant Pennsylvania: "As regards myself I have 
bad news to write and think this probably will be 
my last letter directed to you. I have been troubled 
some time back with a diseased mouth. The French 
doctors in Tahiti call it a ver>- bad cancer and it has 
developed too far to be successfully treated by 
•surgical operation. In fact, it has been so bad and 
painful that life is a burden and for some time I 
have been unable to work in my collection. . . I may 
jiossibly linger along for several months. I am too 
weak to write much, so I will thank you over and 
over again for your past kindness to me. . ."" 

Garrett died on November 1, 1887, and is buried 
in the missionary cemetery under a large tamanu 
tree at the edge of the village of Fare. The grave, 
with an inscribed marker, surrounded by a .small, 
iron fence, still survives and is kept in good repair 
at the expense of the French government. 

It was fortunate that the English minister. Rev. 
Ebenezer V. Cooper, Garrett's neighbor, wrote a 
brief but fairly accurate obituary. It was published 
with a bibliography a few months after the scien- 
tist's death in four different conchological 
magazines, namely "The Conchologist's Exchange", 
"The West American Scientist", "The Journal of 
Conchology" (London) and "Science".' 

The Personality of Andrew Garrett 

What few descriptions we have of this now 
almost forgotten explorer-naturalist give us an 
impression of a sincere and gifted personality. 
Garrett was serious, intelligent, and blessed with 
prodigious energy and drive. Many times he had 
been in great danger and must have had unusual 
physical endurance, having been exposed at sev- 
eral times to shipwreck, tropical diseases, and ex- 
treme fatigue. One of the most striking of his 
characteristics was his ability to overcome the 
handicaps of very limted formal education. His 
missionary friend, the Reverend Ebenezer Cooper 
wrote, "He was self-taught in every sense of the 
word and his ability and achievements were 
wonderful and striking."' He advanced himself in 
reading and he so practiced himself in writing 
that he eventually acquired a commendable and 



Vol. 93 (1) 



January 10. 1979 



THE NAUTILUS 27 



vigorous prose style. His artistic ability, very 
crude at first, with persistent effort enabled him 
to draw not only with scientific precision but 
with aesthetic quality as well. As for languages, 
he could speak Polynesian, at least the Hawaiian 
fonn of it, and probably could use some French 
because of its commercial and social usage in the 
Society Islands where he spent one third of his 
life. 

In appearance, he was a lank, partially bald 
man even in his early thirties, and had deep 
cavernous eyes to judge from the only portrait 
known to exist which he sent to Agassiz at the 
time he was engaged as a collector by the Mu- 
seum of Comparative Zoology at Harvard. He was 
slim, apparently of medium height with slightly 
stooped shoulders, side whiskers and a full beard. 
He looked older than his true age and might have 
passed as a down-at-the-heels missionary or even 
an intellectual beachcomer. One person who knew 
him well remarked, "He was very unpretentious 
and no one from casual observation would im- 
agine him to be a savant. . . Outside, his own 
special study of Conchology, he was deeply read 
in kindred subjects and no brand of natural 
history seems to have been overlooked." In his 
later life he possessed a good working library of 
books and pamphlets in his specialty and these 
books are now preserved in the Bishop Museum 
in Honolulu. 

Although a shy man and apparently not en- 
dowed with an exuberant personality, he instilled 
quiet admiration and even warmth in his close 
friends. Dr. Wesley Newcomb was so pleased 
with him that he promised to name a new species 
of shell in his honor. One of his closest friends, 
William Harper Pease, in innumerable letters be- 
moaned his long absences which often lasted for 
years at a time. His staunch supporter, the mis- 
sionary Damon, was constantly praising him and 
his rare qualities. One of Garrett's defects seems 
to have been his poor luck in business affairs 
and, perhaps, his over confidence in individuals 
whom he trusted who took advantage of him in 
failing to pay their debts. At times, he seemed to 
lack normal assertiveness. 

Encomiums on the accuracy of his scientific 
work have come from a number of sources in- 
cluding Agassiz, Pease, Gunther, and more 



modern scientists such as Herbert H. Smith, 
Alvin Seale, Spencer Tinker and others. Especial- 
ly noteworthy were the statements of the 
authority on Pmiuln tree snails of Polynesia and 
Melanesia, Dr. Henry E. Crampton, Professor of 
Zoology in Columbia University. Crampton made 
at least five expeditions over a period of 18 years 
to many of the islands where Garrett had col- 
lected forty or fifty years earlier. Crampton 
wrote, "But, above all others, the name of Garrett 
stands out prominently. . . the rich fruits of his 
masterly studies are the shells described mainly 
by Pease and the precise descriptions of their 
habitats specified with an exemplary minuteness 
his own notable monograph. . . It is this work of 
Garrett's that forms a solid basis for comparison 
of the present intrinsic and distributional 
characteristics of Polynesian species in their con- 
ditions and situations. . ."" The same appraisal 
has been given by Dr. William J. Clench who said 
that Garrett deserves great credit because he 
recognized the hyperspecific localities and 
realized the value of numerous species from a 
variety of regions. He perceived the changes made 
in a species by changes in topography.'' 

One man, a contemporary from another profes- 
sion but thoroughly familiar with Garrett's field 
work, Rev. Samuel C. Damon, was prophetic 
when in 1863 he wrote: ". . .we are bold to assert 
that there are but a few men in the world whose 
labors are intrinsically of more value to natural 
history. Take for example, his late exploration of 
the Society Islands. It is undoubtedly more im- 
portant than that of any English, French or 
American exploring expedition which ever visited 
these islands. . . We are confident no explorer is 
more worthy of their notice, or has contributed 
more largely to widen the sphere of science and 
knowledge."" 



Acknowledgments 

The author is especially indebted to his late 
cousins, Francelia and Aurilla Leonard of 
Fairhaven, Massachusetts, who gave him a set of 
over 250 watercolors and drawings of fishes and 
shells made by Andrew Garrett. Many scientists 
and museum workers assisted in his forty-six- 
year researches, especially William J. Clench of 



28 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



Harvard University; the late E. W. Gudger of 
the American Museum of Natural History; the 
late Henry E. Crampt^m of Barnard College; 
Peter Buck, Margaret Titoomb, Yoshio Kondo, 
Eklward Br>'an and Donald M. Mitchell, all of the 
B. P. Bishop Museum; Ruth E. Lee and Ann 
Blum, Museum of (x)mparative Zoology, Harvard; 
Spencer M. Tinker of the Waikiki Aquarium; 
Albert Panning of the Hamburg Zoologischen 
Staatsinstituts; Barbara Johnson of Princeton, 
New Jersey; Yosihiko Sinoto of Huahine and 
Aurora Natua of the Papeete Museum; and, for 
assistance for 1961 travel expenses, the Explorers 
Club of New York and the Frank M. Chapman 
Memorial Fund of the American Museum of Nat- 
ural History. Dean Amadon, R. Tucker Abbott 
and many others gave of their time and 
assistance, for which I am very grateful. 



BIBLIOGRAPHIC REFERENCES 

Andrew Garrett's Fische der Sudsee in Journal des 
Museum Godeffroy, Hamburg 1873/7.5 Vol. 1 and 2, Vol. 
3, 1909. written and edited by Albert C. L. G. Gunther. 
Florence M. .Spoehr. White Falcon. Pacific Books. Palo 
Alto. Calif. 196.3. pp. 101-119. 

Ebenezer V. Cooper. "Obituary of Mr. Andrew Garrett" 
in Journal of Conchology (Leeds) 1888, Vol. V: 317-318. 
Also West American Scientist, vol. 4, p. 19. 
Letter from A. G. to James M. Barnard, dated Hilo, 
Hawaii, April 29, 1857. Original in M. C. Z.. Harvard 
University. 

Crew List of the Bark, Edward. Old Dartmouth 
Historical Society, New Bedford. Mass. 
77ie Friend. Honolulu, (newsiiaper) October 13, 18.58 p. 76 
article. "Mr. Andrew Garrett, the Naturalist" by Samuel 
C. Damon. 

Baker, Ray Jerome, "Honolulu in 18,53", Honolulu, 19.50. 
Letter from Dr. Wesley Newcomh to Garrett, Honolulu 
Nov. 27, 18.54. Original in Bishop Museum Library. 
Kay, A. E. "Biography of William Harper Pease in 
Nemouria, Occasional Papers of the Delaware Museum of 
Natural History, no. 16. Dec. .30. 197.5. 
Garrett. Andrew letter to I/iuis .^gassiz. Hilo, Hawaii 
.Jan. 29. 18.5.5. Original in M. C. Z. Harvard University. 
Andrew Garrett to James M. Barnard, dated Hilo, 
Hawaii Oct. 10, 18.5(). Original in M. C. Z. 
The Friend, Honolulu (newspaper), July 1,5, 18.59 p. .52. 
Letter from .John W. Ix>onard to his wife, on board ship 
Lydia, March 2, 18.57. Original in po.ssession of Mrs. Bar- 
bara Johnson, Princeton. N. J. 

Letter from Louis Agassiz to J. M. Barnard (intended for 
Garrett), from Cambridge. Mas.s. .■^ug. 28, 1S.57. Original 
inM.C.Z. 

Letter A. G. to J. M. Biirnanl. I'apai Puna, Island of 
Hawaii,Julyl3,1857. 



10. 

11. 

12, 
13. 



14. 



15. 



16. One of two undated letters from Agassiz, preserved in 
the Andrew Garrett manuscripts in the Library of the 
Bishop Museum. Honolulu, Hawaii. 

17. Greene, K. W. Articles in Hawaiian Shell News. Issues 
of April through October. 1960. Honolulu. Hawaii. 

18. Mrs. James Warren. "The Morning Star": History of the 
Chi Idrens "Missionary Vessel". Boston, 1860. 

19. Letter from A. Garrett to J. M. Barnard containing his 
Kingsmill Island Journal, dated Honolulu. Feb. 8, 1860. 
Original in M. C. Z. Library. Harvard University. 

20. Board of Trustees, Museum of Comparative 2yOology, 
Harvard University. Cambridge, Mass. -fnl Annual 
Report. 1862. 

21. Andrew Garrett "The Terrestrial Mollusca Inhabiting 
the Society Islands" Proceedings of the Academy of 
Natural Sciences of Philadelphia. Journal 9, 1884-1888, p. 
17-114. 

22. Samuel C. Damon article in The Friend, Honolulu. Aug. 
4, 1863. New Series Vol. 2, p. 8. 

23. Andrew Garrett, letter to J. M. Barnard from Hilo, 
Hawaii, April 29, 1857. 

24. W. H. Pease, letter to A. Garrett, Honolulu. Sept 2, 1862. 
Original in Bishop Museum Library. 

25. Letter from W. H. Pease to A. Garrett, Jan. 20, 1864. 
Original in Bishop Museum Library. 

26. A. Panning. "Beitrage zur Geschichte des Zoologischen 
Staatsinstituts und Zoologischen Museums in Hamburg." 
Hamburg Dec. 1956. 

27. Letter from J. C. Godeffroy to Theodor Weber, dated 
Hamburg Jan. 25, 1867, copy provided to WST by his 
descendant Caesar Godeffroy. 

28. Judy Tudor, Editor and Compiler Handbook' of Fiji. 
Fourth Edition. Pacific Publications. Sydney. N. S. W. 
1972 p. 51, .53. .57. 

29. Letter A. Garrett to Dr. W. D. Hartman, West Chester, 
Pa., dated Huahine, Society Islands. Nov. 28, 1878. 
Original in Carnegie Museum. Pittsburgh. See also The 
Bejit of the Nautilus (R. T. Abbott ed.. 1976). p. 260. for a 
similar letter written by W. D. Hartman to H. A. Pilsbry 
about 1896! 

.30. Information supplied by A. Panning of Hamburg 19.55 to 

W. S. Tliomas. 
.31. lietter fnim A. Garrett to J. G. Anthony. Cambridge, 

Ma&s. Sept. 15. 1872 from Huahine. Original in MCZ 

Library, Harvard University. 
32. Introduction by Dr. A. C. L. Gunther to Fi.sche der 

Sudsee. Hamburg, 1873. 
.33. Memo from Alvin Seale M.D. in copy of his book "The 

Golden Cloak" in Library of the Bernice P. Bishop 

Museum, Honolulu. 
31. l^elter from A. Garrett to W. D. HartniJin Feb. 10. 1879 

in Carnegie Museum, Pittsbui'gh, Pa. 

35. I/etter from A. Garrett to W. D. Hartman. dated 
Huahine .June 2.5, 1887. 

36. Cranipton, Henry E. "Studies on the Variation. 
Distribution and of the Genus Partula". Carnegie In- 
stitution, Washington. D.C, 1916, 

37. Clench, William J. Conversation with W. S, Thomas, 
Cambridge, Mass. Nov. 2, 1931. 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 29 



THE NEMERTEAN, MALACOBDELLA GROSSA, IN THE OCEAN 
QVAHOG, ARCTICA ISLANDICA (BIVALVIA) 



Douglas S. Jones 

Department of Geological and Geophysical Sciences 
Princeton University 
Princeton, N.J. 08540 

ABSTRACT 

JTie cornmetisal relationship between the marine bivalve, Arctica islandica, and 
the nemertean Malacobdella grossa along the Atlantic coast of North America has 
not heretofore been reported, although it has been documented in European 
specimens. A single M. grossa was found living in a small Ocean Quahog dredged 
from offshore New Jersey. In addition, the nemertean occurred in the venerid 
clam. Pitar morrhuana,/rom the same locality with a frequency of 28%. Examina- 
tion of numerous specimens of A. islandica /or M. grossa with negative results sug- 
gests this occurrence is atypical. 



The commensal nemertean, Malacobdella grossa 
(Miiller), ranges widely along the North 
American Atlantic coast where several species of 
bivalves are known to serve as hosts. Coe (1943) 
cites Mercenaria mercenana. Mya arenatia. and 
Cras,^ost7ra virginica as known hosts of this com- 
mensal. Porter (1962) added Mercenaria 
campechiensis to this list, and Ropes discovered 
M. gro.fsa in the Morrhua Venus, Pitar mor- 
rhuana. The aforementioned species are among 
seventeen bivalves known to serve as hosts for 
the genus Malacobdella and fourteen for M. 
grossa (Ropes, 1967). 

While Coe (1943) lists Arctica islandica as a 
host of Malacobdella grossa in European waters. 
Ropes (1967) points out that in the western At- 
lantic M. givssa is not known from either Arctica 
islandica or Spisula solidissima, two widely dis- 
tributed and abundant Middle Atlantic coast bi- 
valves (Merrill and Ropes, 1969). This is unusual, 
since Malacobdella occurs in two other species of 
Spisula (S. sachalinensis from Japan and S 
stultorum from Europe). Brunberg (1964), in re- 
porting on nemerteans from Danish waters, says 
Malacobdella grossa was commonly collected in 
the mantle cavity of Cyprina (now Arctica) is- 
landica in the areas investigated, i.e., the 
Gullmarfjord, the neighborhood of Frederikshavn 
and Laes^, in the northern J0resund. Nevertheless, 



Ropes (1967) reports examining thousands of surf 
clams and numerous ocean quahogs from the At- 
lantic coast with negative results. 

METHODS 

Specimens of Arctica islandica were obtained 
on 27 June 1977 by a commercial clamming vessel 
fishing with a "hydraulic clam dredge at a loca- 
tion ('^73°40'W and 40°15'N) approximately 32 
kilometers offshore from Asbury Park, New 
Jersey, in water 30 meters in depth. Several 
specimens of Pitar motrhuana were caught with 




FIG. 1. Arrows shmv the nemertean. Malacobdella grossa at- 
tached to the mantle of the Ocean Quahog. Arctica islandica 
after removing the left, valve and visceral mass. Scale at right 
has centimeter divisions. 



30 THE NAUTILUS 



January 10, 1979 



Vol. 93 (1) 



the ocean quahogs in the same dredge hauls. 
Twenty ocean quahogs of various sizes and 18 
specimens of P. morrhuana were randomly 
selected from the dredge hauls, opened in the 
laboraton,'. and examined. Shell lengths were 
measured and the soft body tissues searched for 
other organisms. When the single nemertean, 
MnlacdhdeUa groni^a, was discovered in an in- 
dividual Arctica i'slandica, it was identified, 
measured, photographed, and preserved. 



RESULTS 

A single specimen of Airtira Mandicn con- 
tained the commensal nemertean Malacobdella 
grossa living in its mantle cavity (Fig. 1). The 
clam, a smaller individual than those normally 
caught, had a shell-length of 55 mm. The nemer- 
tean was easily recognized by the presence of a 
ventral, rear sucker found attached to the mantle 
of the clam, hi a relaxed live state it measured 21 
mm in length. Of the eighteen specimens of Pilar 
morrhuana collected from the same dredge haul, 
five contained individuals of M. grossa for an in- 
cidence of infection of 28%. Shell-lengths of the 
Pitar specimens ranged from 39 mm to 58 mm 
and averaged 44 mm while M. grossa occurred in 
individuals ranging from 41 mm to 58 mm. The 
worms ranged between 20 and 28 mm in length 
and each host contained only a single nemertean. 



DISCUSSION 

The single occurrence of Malacobdella grossa in 
an individual of Arctica islandica is apparently 
very rare for the Atlantic coast of the United 
States and Canada. Though Brunberg (1964) 
found ocean quahogs commonly hosting M gmssa 
in Danish waters, no incident of this relationship 
has ever been reported on this side of the Atlan- 
tic. Ropes (1967, personal communication) has ex- 
amined numerous specimens of Arctica without 
finding any evidence of infection by M. grossa. In 
addition, I have opened almost one thousand 
specimens of Arctica islandica and Spisula 
solidissima for various research purposes without 
encountering another nemertean. 



The single infected clam was smaller than 
those usually caught by commercial clamming ap- 
paratus and hence smaller than those usually ex- 
amined. It was similar in size to the infected in- 
dividuals of Pitar morrhuana collected in the 
same dredge haul. Nevertheless, numerous com- 
parably-sized Arctica have been examined with 
negative results. Examination of hundreds of 
specimens of both surf clams and ocean quahogs 
for M. grossa has, except for this one incident, 
yielded negative results. The evidence supports 
Ropes' (1967) conclusion that Malacobdella grossa 
does not normally associate with either Spisula 
solidissima or Arctica islandica along the Atlan- 
tic coast of North America. 

ACKNOWLEDGMENTS 

I would like to thank Mr. John Ropes of the 
National Marine Fisheries Service for critically 
reading the manuscript and Dr. Donald Baird of 
the Princeton Natural History Museum for 
photographing the specimen. The cooperation of 
Snow Foods. Inc. of Pt. Pleasant. N. J. is greatly 
apprec-iated. This report is an outgrowth of other 
work on neritic bivalves supported by NOAA Sea 
Grant #04-6-158-44076 to Dr. Ida Thompson of 
Princeton University. 



LITERATURE CITED 

Brunberg. L. 19&4. On the nemertean fauna of Danish waters. 
Ophelia 1:77-111. 

Coe. W. R. 1943. Biology of the nemerteans of the Atlantic 
coast of North America. Trans. Cotmecticut Acad. Arts Sci. 
35:129-328. 

Merrill. A. S. and .J. W. Ropes. 1969. The general distribution 
of the surf clam and ocean quahog. Pivc. Natl Shellfish. 
Assoc. 59:40-45. 

Porter. H. .1. 1962. Incidence of Malacobdella in Mercenaria 
campechiensis off Beaufort Inlet. North Carolina. Pmc. 
Nat I Shellfish. Assoc. 53: 133-145. 

Ropes, J. W. 1%7. Malacobdella grossa in Pitar morrhuana 
and Mercenaria campechiensis. The Nautilus 81:37-40. 

. 1966. Pitar morrhuana, new host for 



Malarobdetla grossa. The Nautilus 79:128-130. 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 31 



DEPTH DISTRIBUTION OF THREE GASTROPODS IN NEW MISSION BAY. 

LAKE MICHIGAN 

Gary L. Pace, Ernest J. Szuch and Richard W. Dapson 

Biolog>' Department, University of Michigan-Flint 
Flint, Michigan 48503 

ABSTRACT 

SCUBA was used in August, 197^. to determine the depth-distribution of mails 
at two localities in New Mission Bay, a small inlet of Grand Traverse Bay. Lake 
Michigan. Five 0.5m^ samples were collected at 20 ft intervah along each of 6 
depth contours at both localities (5. 10, 15. 20, 25. 30 ft and 10, 12.5, 15, 20, 25, 30 
ft). At the 2 localities Gyraulus parvus (Say) attained peak densities of 2.U/m} and 
28.Jt/m^ on small pebbles at 10 ft depths. These densities represent 60% and 92% of 
the Gyraulus collected at the two localities. Most Marstonia decepta (Baker) fAm- 
nicola lustrica of Pilsbry) and Valvata tricarinata (Say) were collected from sand- 
silt .wbstrates. Both M. decepta and V. tricarinata reached their maximum den- 
sities at the 10 ft depth at one locality (16i.8/m^ and 29.6/m^, respectively), and at 
the 12.5 ft depth at the other (152.i/m^ and h9.2/m^, respectively). These densities 
represent 60% and 5k%> of the M. decepta and 37% and 30% of the V. tricarinata 
specimens collected fiv7n the two localities. 



Most studies of Great Lakes' macrobenthos 
have understandably been large scale dredging 
operations dealing primarily with profundal 
organisims (Eggleton, 1936, 1937; Mema, 1%0; 
Powers and Robertson, 1965; Robertson and Alley, 




FIG. 1. Location ofNew Mission Bay (mmicin inset). 



1966; Henson, 1966) or with specimens collected 
from the upper littoral zone and beach drift 
(Goodrich, 1932; Heard, 1962a, 1962b; Henson and 
Herrington, 1965). Beach drift specimens, of course, 
tell us very little of the preferred habitat, and a 
number of papers have demonstrated problems 
with the reliability and efficiency of several types 
of bottom samplers (Beeton, Carr, and Hiltunen, 
1965; Milbrink and Wiederholm, 1973). ahers 
have shown, however, that, visibility permitting, 
SCUBA-assisted studies can provide direct, quan- 
titative collections from a wide variety of 
substrates (Cvancara, 1972; Harmon, 1972; Clam- 
pitt, 1973, 1974). This paper reports on a SCUBA 
study of the depth distribution of 3 littoral 
gastropod species at 2 discrete localities in New 
Mission Bay, a small inlet on the western side of 
Grand Traverse Bay, Lake Michigan (Fig. 1). 

New Mission Bay narrows irregularly from a 
maximum width at its mouth of about 2.3 km, 
due North for a distance of approximately 1.7 km 
(Fig. 2). A paved road circumscribes the bay 
within a few hundred meters at all points. Be- 
tween the road and the bay, mixed coniferous- 
deciduous woods dominate along the east shore 
and alternate with cleared land on the west and 



32 THE NAUTILUS 



January 10, 1979 



Vol. 93 (1) 




FIG. 2. Cantimr map of New Mission Bay showing positions 
of Oniena Beach and Oniena-T)ni'erse Yacht Club collecting 
localities (adapted from U.S. Army Corps of Etiyiiieers Chart 
LS. 706). Scale = ■5(X)ft/unit: Contour Interval = 6fi. 

north shores. The very small town of Omena with 
its marina and public beach rests at the bay's 
Northwest comer while a few cottages, perma- 
nent residences and a yacht club are scattered 
among the trees along the east shore. The bot- 
tom-slopes are ver>' gradual on both sides at the 
outer end of the bay. On the western side of the 
inner half of the bay, however, the bottom-slope 
is at first very gradual and then drops off 
abruptly. While there are local differences 
discussed below, the northern and northeastern 
bottom-slopes deepen rather regularly. Within 
New Mission Bay, only one region in the north- 
west corner is known to exceed 60 ft in depth 
(Fig. 2). Temperature measurements of 21° C 
down to 30 ft and 20° C at 40 ft were recorded in 
the northeastern part of the bay on August 17, 
1974. These correspond well with Lauffs (1957) 
data for this region of (Jrand Traverse Bay. 
Lauffs report also provides a Secchi disk trans- 
parency measurement of 9-10 m and notes that sur- 



face currents pass the mouth of New Mission Bay 
in a WSW direction at this time of year. 

MATERIALS AND METHODS 

SCUBA was used to study the depth distribu- 
tion of snails along two "transects" in New Mis- 
sion Bay (Fig. 2). One, designated "Omena Beach" 
(O.B.), runs south from a point about 100 yds east 
of the public beach at the northern end of the 
Bay. Here the bottom-slope increases gradually in 
depth to about 15 ft and then drops off rapidly to 
depths greater than 60 ft. The predominantly 
sandy bottom gradually becomes overlain by a 
thin layer of colloidal organic sediment as the 
depth increases. The second transect, "Omena- 
Traverse Yacht Club" (Y.C.), extends west from 
the east shore about ,50 yds. south of the yacht 
club. The bottom here is strewn with large boul- 
ders at the edge and increases rapidly in depth to 
about 10 ft where the substrate becomes sandy 
and the slope levels off for 100-150 ft. Here the 
organic content of the substrate increases as the 
depth increases rapidly to more than 45 feet. 
Macrophjtes were essentially nonexistant at both 
study areas. 

Each transect consisted of six 100 foot lines 
marked at 20 ft intervals and placed approx- 
imately parallel to shore along depth contours. 
These were established at depths every 5 feet out 
to 30 feet at Omena Beach, and 10 ft", 12.5 ft, 15 
ft, 20 ft, 25 ft, and 30 ft off the Yacht Club. 
Depths were determined using a calibrated line 
tied to a float and were checked using diver's 
depth gauges. A sand-filled "Hula-Hoop" was se- 
quentially placed at the center of each 20 ft sec- 
tion establishing a constant sample area (0.4KmM. 
Hand-picked snails were placed into prelabeled 
"zip-lock" type plastic bags. Thirty snail samples 
were thus collected directly from each of the two 
study areas. 

RESULTS 

The following mqllusks, in order of decreasing 
maximum density (X/m'), were collected from the 
two localities: Marstonia deceptn (Baker) (.4m- 
nicola lustrica of Pilsbry) (164.8), Valrata 
tricarinata (Say) (49.2), Gifraulus parvus (Say) 
(28.4), Physa .sp. (3.6), Pisidium sp. (2.4), Cinciri- 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS aS 



TABLE 1. Depth Distribution <\f Snails near Omena Beach. Data are mean den^ties (^/m') nf 5 samples (n =.V at each depth, 
with Standanl Enrrr (SE) in parentheses: % of the species-populatian at each depth: % nf the snail community at each depth 
represented by each species. 



Species 


Depth 


fx/m§f(SE) 
0.0 


% 


% 




(ft) 
5.0 


Species 
0.0 


Community 


G. parvus (Say) 


0.0 




10.0 


2.U ( 1.3) 


60.0 


1.2 




15.0 


0.0 


0.0 


0.0 




20.0 


0.8 ( 0.7) 
0.8 ( O.k) 


20.0 


3.6 




25.0 


20.0 


1.5 




30.0 


0.0 


0.0 


0.0 


H. decepta (Baker) 


5.0 


7.6 ( 1.3) 


2.8 


40.4 


(= A. lustrica Pllsbry) 


10.0 


164.8 (Ik.k) 


59.8 


83.7 




15.0 


W.it ( 5.2) 


16.1 


68.1 




20.0 


18.0 ( 2.0) 


6.5 


80.3 




25.0 


38.0 (14.;+) 


13.8 


72.5 




30.0 


2.8 ( 1.3) 


1.0 


67. 5 


V. trlceirinata (Say) 


5.0 
10.0 


11.2 ( 1.7) 
29.6 ( 3.7) 


14.1 
37.4 


59.6 
15.1 




15.0 


20.8 ( 7.6) 


26.3 


31.9 




20.0 


3.6 ( 1.6) 
13-6 ( 7.3) 


4.5 


16.1 




25.0 


17.2 


26.0 




30.0 


0.4 ( 0.4) 


0.5 


12.5 



natia cincinnatiensis (Anthony) (2.0), Goniobasis 
livescens (Menke) (1.2), Lymnaea decampi 
(Streng) (0.8), LampsUis mdiata .vliquoidea 
(Barnes) (0.2), Anodonta graudis (Say) (0.1). Due 
to the substantial differences in relative abun- 
dance, only the data for the first three species are 
presented (Tables 1, 2, Figures 3-6) in any detail. 

Gip-aulus parvus, rarest of the three most 
prominent species, was most commonly found on 
the sand-gravel substrates at 10 ft in both 



localities. Densities of 2.4/m^ and 28.4/m^ repre- 
sent 60% and 92.2% of the specimens collected at 
O.B. and Y.C., respectively (Tables 1, 2). Thus, at 
10 ft, Gijraulus represented only about 1% of the 
3-species community at O.B., but as much as 30% 
of that community at Y.C. The distribution of 
Marstonia decepta at Omena Beach (Table 1, Fig. 
3) appears bimodal, with a major peak at 10 ft of 
164.8/m^ and a minor one of 38/m^ at 25 ft. At 
the Yacht Club locality (Table 2, Fig. 4), however, 



TABLE 2. Depth Distribution of Snails near Omena-Traverse Yacht Club. Data are mean densities (X/m^) of 5 samples (n=.5) 
at each depth, with Standairl Error (SEj in parentheses: % of the species-population at each depth: % of the snail cornmunity at 
each depth represented by each speciex. 

% % 



Species 


Depth 


Dens] 


ty 




(ft) 

10.0 


(X/m2) 

28.4 


(SE) 


G. parvus (Say) 


7.8) 




12.5 


0.4 


0.4) 




15.0 


0.4 


0.4) 




20.0 


0.8 


0.7) 




25.0 


0.4 


0.4) 
0.4) 




30.0 


0.4 


H. decepta (Baker) 


10.0 


60.4 


6.1) 


(=A. lustrica Pilsbry) 


12.5 


152.4 


11.7) 




15.0 


46.8 


12.1) 




20.0 


11.2 


2.2) 




25.0 


8.8 


2.7) 




30.0 


4.0 


1.8) 


V. tricarinata (Say) 


10.0 


5.2 


0.9) 




12.5 


49.2 


6.8) 




15.0 


29.6 


4.8) 




20.0 


38.0 


4.6) 




25.0 


27.2 


6.9) 
4.4) 




30.0 


12.4 



Species 


Community 


92.2 


30.2 


1.3 


0.2 


1.3 


0.5 


2.6 


1.6 


1.3 


1.1 


1.3 


2.4 


21.3 


64.3 


53.7 


75. '^ 


16.5 


61.0 


4.0 


22.4 


3.1 


24.2 


1.4 


23.8 


3.2 


5.5 


30.5 


24.4 


18.3 


38.5 


23.5 


76.0 


16.8 


74.7 


7.7 


73.8 



34 THE NAUTILUS 



January 10, 1979 



Vol. 93 (1) 



200, 



150. 



/ m 



100 



50 



I 



M. dec ept a 



tt 



01 I I I I 

5 10 15 20 25 30 



4=. 



ft 

FIG. 3. Depth distributimt of Marstonia decepta at Omena 
Beach. Horiznnal Line = X/m': Vertical Bar = ± 1 Standard 
Error; Vertical Line = Range of density among 5 samples at 
each depth. 

Marstonia shows a definitely unimodal distribu- 
tion with a maximum density of 152.4/m^ at 12.5 
ft. These ma.ximum densities represent nearly 
60% of the Omena Beach specimens and almost 
54% of the Yacht Club specimens taken from the 
6 depths at each locality. Marstonia was obvious- 
ly the dominant member of the molluscan com- 
munities of the 5 deeper stations (68-87%) at O.B. 
(Table 1) and of the 3 shallower stations (61-75%) 
at Yacht Club (Table 2). 

Valvata tricarinata appears to demonstrate 
bimodal distributions at both localities, but with 
distinct maxima in each case. At Omena Beach 
(Table 1, Fig. 5), Valvata reached its peak density 
of 29.6/m^ at 10 ft. After decreasing rapidly from 
20.8/m^ at 15 ft to 3.6/m^ at 20 ft, Valvata in- 
creased again to 13.6/m' at 25 ft. A similar, but 
less dramatic bimodal distribution was found at 
the Yacht Club site (Table 2, Fig. 6). Here, the 
maximum density (49.2/m') occured at 12.5 ft. 
This declined to 29.6/m' at 15 ft and increased 



again to 38.0/m^ at 20 ft. The maximum densities 
represent only about 37% of the specimens col- 
lected at Omena Beach and less than 31% of the 
specimens taken at the Yacht Club site. V.alvata 
was the dominant member of the communities of 
the 5 ft station at Omena Beach (Table 1) and of 
the 3 deeper stations off the Yacht Club site. 
(Table 2). 

DISCUSSION 

The paucity of similar studies prevents the 
direct comparison of these data with those of 
others and the causes for the demonstrated 
stratification can only be surmised. Since all sta- 
tions were within the elipimnion, the chemistry 
of these environments would be expected to be 
rather homogeneous. Physico-chemical differences 
in the benthic microhabitats, if they e.xist, may 
therefore be assumed to be the direct result of 
substrate-biota interactions. Harman (1972), 
reporting on mollusks from three central New 
York lakes, suggested that definite relationships 

-200. 



X/2 

/m 



•>'»<■. 




M. dec epia 


150. 


1 




100. 






50. 


^^ 


f 


0. 




+ 4-1 



10 



15 20 25 
ft 



30 



FIG. 4. Depth distribution of Marstonia decepta at Omena- 
Traverse Yacht Cluh. 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 35 



exist between mollusk distribution and substrate 
patterns. The substrates of ail our stations fall 
into one of his five broad types: "Littoral silt and 
detritus -fine organic and inorganic materials." 
According to Harman, this is the preferred sub- 
strate of only one of our three species, namely 
Valvata tricarinata. The other two species, 
Gip-aulus panms and Mastnnia decepta are said 
to prefer "Autochthonous organic matter - aquatic 
plants and their decaying remains." 

Of 121 collections of Gip-avbis [mrvus by Har- 
man (1972), 94 were from substrates of auto- 
chthonous organic matter, while only 9 were from 
littoral silt and detritus. Considering that there 
were no aquatic macroph>1:es near any of the sta- 
tions we studied, it is perhaps surprising the 
Gyranlus were found to represent as much as 
30% of the molluscan community at the 10 ft 
depth of the Yacht Club locality. This was, 
however, the only station in which Gip'aulus was 
at all common. As indicated above, Gyrmdus was 
frequently collected from small pebbles rather 
than from the more abundant sand and flocculent 
organic sediments. This may reflect the require- 
ment of a more stable substrate usually available 
in the form of higher aquatic plants in these 
snails' preferred habitats. 

Three observations suggest that major com- 
ponents of the niches of Marstonia decepta and 
Valvata tricarinata overlap: (1) the occurrence of 



60, 



4 



y, 



V2 



20 



V. tricarinata 



I 



t 



11 



5 10 15 20 25 30 

ft 

FIG. 5. Depth distribution of Valvata tricarinata at Omena 
Beach. 



80. 



60 



X/ 2 ''O 
/m 



20. 



V. tricarinata 



W 



\\\ 



-f 



+ 



5 to 15 20 25 30 

ft 

FIG. 6. Depth distribution of Valvata tricarinata at 
(hnertn-Tnwerse Yacht Club. 

both species at all our collecting stations; (2) the 
co-occurrence of the peak densities of these two 
species at 10 ft (O.B.) and 12.5 ft (Y.C.) indicating 
the preferred conditions for both species; (3) the 
co-occurrence of secondary density peaks at the 
25 ft depth at O.B. That Marstonia is better 
adapted to the conditions in New Mission Bay is 
indicated by the fact that it was the dominant 
species in 8 of the 12 communities studied. Since 
a higher percentage of the Marstonia specimens 
were collected at the 10 ft (60%) and 12.5 ft (54%) 
depths, we might infer that this species has a 
stronger preference for (i.e., is better adapted to 
the) conditions at these depths than is Valvata 
(37% & 31%). At neither location did Valvata 
(15% & 24%) dominate the communities of these 
depths. At Omena Beach, Valvata dominated only 
the 5 ft depth, while Marstonia dominated all 5 
greater depths. Off the Yacht Club however, Mar- 
stonia donated all three shallower depths, while 
Valvata was obviously the dominant member of 
the three deeper communities. Thus it seems that 
Marstonia is not only generally better adapted to 
the New Mission Bay conditions, but specifically 
best adapted to those at the 10-12.5 ft depths. 
Valvata, on the other hand, seems less spe- 
cialized, but better able to take advantage of the 



36 THE NAUTILUS 



January 10. 1979 



Vol. 93(1) 



marginal habitats where Marstonia densities are 
low (5 ft-O.B.; 20, 25. 30 ft - Y.C.). Thus Mar- 
stonia decepta often outnumbers Valvata tricar- 
inata in a littoral silt and detritus habitat. This 
directly contradicts Harman's (1972) statements 
as to the substrate preferences of these two spe- 
cies, and demonstrates the care which must he 
observed when attempting to apply the findings 
of those working on inland lakes in contrast t<i 
those dealing with the ecology of the Great 
Lakes. 

ACKNOWLEDGMENTS 

The authors express their deepest appreciation 
to Dr. Lee H. Somars. Director, Underwater 
Technology Laboratory and the Michigan Sea 
Grant Program for providing technical assistance, 
as well as the compressed air required for 200 
man-hours of underwater work carried out dur- 
ing this study. The cooperation of the Omena- 
Traverse Yacht Club is also gratefully acknow- 
ledged. In addition, the assistance of our research 
assistant, Gregory Panos, III, and student 
assistants John Kerr and Larry Stevens was essen- 
tial to the completion of the underwater sampling. 
This research was supported by a grant from the 
University of Michigan-Flint Faculty Research 
and Special Projects Committee. 

LITERATURE CITED 

Beeton, A. M., J. F. Carr, and J. K. Hiltunen. 1965. Sampling 
efficiencies of three kinds of dredges in southern Lake 
Michigan. Great Lakes Res. Div.. Univ. Mich.. Puhl. 13: 209. 
(Abstr.) 



Qampitt, P. T. 1973. Substratum as a factor in the distribu- 
tion of pulmonate snails in Douglas Lake, Michigan. 

Mdncihyia 12: .■?79-399. 
1974. Seasonal migratory cycle and related 

movements of the fresh-water pulmonate snail, Physa In- 
tegra. Amer Mull. .Xattir. 92: 27.5-300. 
Cvancara, A. M. 1972. Lake mussel distribution as determined 

with SCUBA, fi-o/oyy 53: 1.54-1.57. 
ICggleton, F. E. 19:36. The deep-water bottom fauna of 

Lake Michigan . Papers Mich. Acad. Sci. 21:.599-612. 
19.37. Productivity of the profundal benthic 

zone in Lake Michigan. PapcrsMich. Acad. Sci. 22: .593-611. 
Goodrich, C. 19.32. The Mollusca of Michigan. Univ. Mich. 

Miiseum Zool. Handbimk Series 5: 1-120. 
Harman, W. N. 1972. Benthic substrates: their effect on 

fresh-water Mollusca. Ecnhigy 53: 271-277. 
Heard, W. H. 1962a. The Sphaeriidae (Mollusca: PelecyTxxla) 

of the North American Great Lakes. Amer. Midi. Naiur. 

67: 194-198. 
1962b. Distribution of Sphaeridae (Pelecypoda) 

in Michigan, U.S.A. Malacaloyia 1: lXi-161. 
Henson, E. B. 1966. A review of Great Lakes benthos research. 

Great Ijikeli Res. [Hr.. Univ. Mich.. Piihl. 14: 37-54. 
Henson. E. B. and H. B. Herrington. 196.5. Sphaeriidae 

(Mollusca: Pelecjiwda) of Lakes Huron and Michigan in the 

vicinity of the Straits of Mackinac. Great Lakes Res. Div., 

Univ. Mich.. PiM. 13: 77-95. 
Lauff, G. H. 1957. Some aspects of the physical limnology of 

Grand Traverse Bay. Great Lakes if&s. Div., Univ. Mich., 

PHbl.2: 1-.56. 
Merna. J. W. 1960. A benthological investigation of Lake 

Michigan. MS Tliesi.'i. Michiyan State Univ. 74 pp. 
Milbrink, G. and T. Wiederholm. 197.3. Sampling efficiency of 

four types of mud bottom samplers. Oikus 24:479-482. 
Powers, C. F. and A. Robertson. 1965. Some quantitative 

aspects of the macrobenthos of Lake Michigan. Great Lakes 

Res. Div., Univ. Mich. Ptihl. 13: 153-1.59. 
Robertson, A. and W. P. Alley. 1966. A comparative study of 

Lake Michigan macrobenthos. Limnology and Oceanography 

11: .576-583. 



ARION SUBFUSCUSm SOUTHEASTERN MICHIGAN 

Dorothy Blanchard 

2014 (leddes Avenue 

Ann Arbor, Michigan 48104 

and 

Lowell L. Getz 

Department of Ecologv', Ethology and Evolution 

University of Illinois, Urbana, Illinois (ilSOl 



The North American distribution of the in- 
troduced European slug, Ariati t^ubfiisais 
(Draparnaud), has been described by Chichester 



and Getz (1968. 1969). Getz and Chichester (1971) 
and Getz (1974). In general, the species occurs 
throughout northeastern United States and 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 37 



southeastern Canada, in the vicinity of Washing- 
ton, D. C, and in the Kipawa Reserve in eastern 
Canada. The latter record represents the furthest 
westward locality previously known for the 
species. A recent discovery of A. mbfuscus in 
Ann Arbor and Allen Park, Michigan, is there- 
fore worthy of note. It extends the known range 
of the species to include the Great Lakes region. 

Specimens of the species were first found by 
the senior author in her yard located within the 
city limits of Ann Arbor. Subsequent investiga- 
tions revealed the species to be present in some, 
but not all, adjacent yards, as well as in Allen 
Park, a suburb of Detroit. It has not been re- 
ported elsewhere in the Ann Arbor or Detroit 
area, however. All individuals collected were 
bright orange and resemble Color Form Three as 
described by Qiichester and Getz (1969). 

The Blanchard's yard contains extensive un- 
cultivated planting of native and introduced 
species of herbaceous plants, shrubs and trees. 
Arion fasciattis (Nilsson) has been present in the 
yard for years, but .4. ftuhfmcus was first noticed 



in 1973. It is not known how the species became 
established in Ann Arbor; most dispersal of 
European slugs apparently occurs during trans- 
jiort of nursery stock (Chichester and Getz, 1969). 
In all regions except Michigan and Washington, 
D. C, A. subfuscus occurs in natural woodland 
habitats as well as in association with human 
habitation. Chichester and Getz (1969) have 
predicted that A. subfusctts will become 
established in natural habitats throughout most 
of North Central United States and South Cen- 
tral Canada. 



LITERATURE CITED 

Chichester. L. F. and L. L. Getz. 1968. Terrestrial slugs. The 

Biologist 5<i:14S-im. 
. 1969. The zoogeography and ecology of arionid 

and limacid slugs introduced into Northeastern North 

America. Malacologia 7:313-.346. 
Getz. L. L. 1974. Arion .mbfuscus in the vicinity of 

Washington, D. C. The Nautihts 88:66. 
Getz, L. L. and L. F. Chichester. 1971. Introduced Slugs. The 
Biologist 53:118-12:1. 



THE ASIATIC CLAM, CORBICULA MANILENSIS, 
FROM TWO RESERVOIRS IN EASTERN TEXAS. 

David Pool and Jack D. McCullough 

Department of Biology 

Stephen F. Austin State University 

Nacogdoches, Texas 75962 



Specimens of the Asiatic Clam, Corbicula 
manileriftis (Philippi), were collected on several 
dates during 1977 from Lake of the Pines Reser- 
voir in the Big Cypress River Basin, Texas, and 
from Murvaul Reservoir in the Sabine River 
Basin, Texas. The species has not been previously 
reported fi'om either reservoir. Specimen at Lake 
of the Pines Reservoir were collected approx- 
imately one kilometer from the dam at a depth of 
less than one meter, on substrates of sand, fine 
gravel and very hard packed red clay. Collections 
at Mur\aul Reservoir were made approximately 
100 meters from the dam in a substrate of sand, 
at water depths also not greater than one meter. 
While the population densities of the clam were 
great in both reservoirs, the largest numbers 
were found at a depth of approximately one 



meter during the summer months, and at the 
water's edge during the winter months. 

The mean values for physico-chemical para- 
meters determined during 1977 (Table 1.) indi- 
cate both reservoirs have good water quality, 
and the fertility of both bodies of water are 
classed as mesotrophic. Preserved specimen have 
been deposited in the Invertebrate collection at 
Stephen F. Austin State University. 

TABLE 1. Meciri values for physico-chemical parameters re- 
corded for Lake of the Pines and Murvaul Reservoirs 
during 1977. 



















^^ 




NO3-N 
(PPM) 


PO4 
(PPM) 


02 

(PPM) 


NH3-N 
(PPM) 


CI 

(PPM) 


Turbidity 
(NTU) 


(PPM) 


Ca 
(PPM) 


Murvaul 


0.10 


0.09 


7.4 


0.42 


23.1 


8.7 


19.5 


4.1 


Lake of 
the Pines 


0.0« 


0.44 


6.8 


0.51 


19.2 


1.9 


22.8 


9.4 



38 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



EVIDENCE FOR TIDALLY CORRELATED FEEDING RHYTHMS 
IN THE EASTERN MUD SNAIL, ILYANASSA OBSOLETA 

J. Roy Robertson 

University of Georgia 

Marine Institute 

Sapelo Island, Georgia 31327 

ABSTRACT 

The occurrence of the crystalline style in an intertidal population of the mud 
snail, Ilyanassa obsoleta, 7vas found to be correlated mth the stage of the tide. At 
bnv tide irhen the snails were exposed almost no individuals sampled possessed 
styles, while during high tide when the snails were covered almost all individuals 
sampled possessed styles. The presence or absence of a style occurred concomi- 
tantly with the presence or absence of fond in the digestive tract. These observa- 
tions suggest that I. obsoleta individual can possess cyclical, discontinuous feeding 
rhythms, .'similar to those that have been observed in intertidal bivalves and one 
other gastropod species. 



The digestive processes of certain intertidal 
bivalve species and the marine pulmonate 
gastropod, Amphibola crenata, from New 
Zealand, have been shown to be cyclical and cor- 
related with the state of the tide (Morton 1956; 
Morton 1971, 1973 1975a, 1975b, 1977; Bernard 
1973; Langton and Gabbott 1974). In particular, 
the studies on intertidal bivalves have shovra that 
the crystalline style dissolves when the animals 
are exposed at low tide and reforms when they 
are subsequently inundated. Although the mud 
snail, Eyanassa obsoleta (Say), is a member of the 
typically carnivorous, rachiglossan Gastropoda, it 
is primarily a deposit feeder (Scheltema 1964). As 
an adaptation to this mode of foraging, /. obsoleta 
possesses a crystalline style which aids in the 
digestion of microflora inhabiting the ingested 
substrate (Brown 1969). This note presents 
evidence for the cyclical dissolution and reforma- 
tion of the crystalline styles belonging to 
members of an intertidal population of /. obsoleta 
in southeast Georgia. 



Contribution No. 380 from the University of Georgia 
Marine Institute. 



MATERIALS AND METHODS 

On November 18 and 19, 1977, /. ob.wleta in- 
dividuals were collected during various tidal 
stages in a slough located on the eastern side of 
Sapelo Island, Georgia. Appro.ximately the same 
tidal level of the shore was sampled at each 
sampling period. The maximum depth of water 
during subtidal sampling periods was 30 cm. 

Sampling was done by placing a line, marked 
at one meter intervals, parallel to the shore line. 
At randomly selected intervals 10 X 10 cm, 
square quadrats were inserted into the substrate. 
All of the snails, buried or on the surface, were 
removed from each quadrat sampled. Enough 
quadrats were sampled so that the total number 
of snails collected at each sampling period ex- 
ceeded 50. Fifty snails were immediately selected 
at random from the main sample. Each specimen 
was processed in the field according to the follow- 
ing protocol: 1) shell length was determined, 2) 
snail was carefully removed from its shell by 
fracturing the shell with a portable vise, 3) style 
sac was opened with fine forceps and the 
presence or absence of a style was noted, 4) snail 
was placed in vial containing acid Bouin's fix- 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 39 



ative. The total time from collection to final pro- 
cessing did not exceed 45 minutes. The contents 
of the digestive tracts of preserved snails were 
determined later in the laboratory. 

RESULTS AND DISCUSSION 

Figure 1 shows that the occurrence of the 
crystalline style in the study population is 
definitely correlated with the tidal cycle. Diel 
variations in temperature and light do not ap- 
pear to modif>' this correlation. Air temperatures 
ranged fi'om 24°C in the daytime to VZ'C just 
before sunrise while water temperatures varied 
between 19° - 15°C. The lengths of the snails 
sampled ranged from 17-21 mm, indicating that 
the population under investigation comprised on- 
ly mature adults (Scheltema 1964). 

The presence of the crystalline style in /. ob- 
soleta is correlated with the type of food eaten 
(Brown 1969). The style is absent in snails 
feeding actively on the flesh of animals while it 
is invariably present in those snails ingesting 
sandy or muddy substratum. In this study all of 
the snails with styles had mud present 
throughout their digestive tracts while the caecae 
and style sacs of the snails which did not possess 
styles were devoid of any type of food. In some of 
the latter snails, mud was found in the posterior 
portions of the intestine and the rectum. 




100- 
90- 



I 50 

* 40- 

i =0 

z 

w 20- 



Mvai of tranMci 



I I I I 

leoo zooo 



^tH — I — I — I — I I 1 

2200 2400 0200 0400 0600 0800 



FIG. 1. Occurrence of the crystalline style in an intertiiM 
population of Dyanassa obsoleta. Upper curve represents tidal 
cycle urith horizontal line indicating position of sampling 
tnmsect relative to tide. Arrows indicate time sample taken. 



Thus the correlation of the occurrence of the 
crystalline style with the tidal cycle in the 
population investigated appears to reflect 
cyclical, discontinuous feeding activities similar 
to those noted previously for bivalves and the 
mud-dwelling, marine pulmonate, Amphibola 
erenata. The results of the present study comple- 
ment those showing that the locomotor activity of 
/. obsoleta is ma.ximum during periods of high 
tide and minimum during periods of low tide 
(Stephens, Sandeen and Webb 1953). 

While this study was restricted to a single 
population of mud snails and one sampling date, 
it does show that /. obsoleta individuals can 
possess discontinuous feeding rhythms correlated 
with the tidal cycle. Further work needs to be 
done on the seasonal variability of foraging 
rhythms (Morton 1975b, 1977) as well as the ef- 
fects of substrate type, resource density and size 
of individual on feeding patterns. 

It is interesting to note that the feeding cycle 
of the marine pulmonate, Amphibola erenata, is 
qualitatively different from that of /. obsoleta. 
While the latter restricts its feeding activities to 
periods when it is covered by the tide, Amphibola 
forages primarily during low tide or high tides 
occurring at night (Morton 1975b). These dif- 
ferences may reflect different adaptations to 
predation by visually orienting predators which 
follow the incoming tide (e. g. crabs and fish). 
The lack of operculum may make it adaptive for 
Amphibola to bury in the substrate when aquatic 
visual predators are most active (high tide during 
the day). 

Ilyanassa, on the other hand, possesses both a 
durable shell and an operculum. These attributes 
might provide sufficient protection from preda- 
tion to allow the snail to forage when aquatic 
predators are active. The factors limiting the 
' foraging activity of Eyanassa to periods when 
they are covered with water may be desiccation 
stress (Schaefer, Levin and Milch 1968; Schaefer, 
Milch and Levin 1968) or the need to ingest a 
substrate with a sufficiently high moisture con- 
tent to facilitate digestion. 



40 THE NAUTILUS 



January 10, 1979 



Vol. 93 (1) 



I 



LITERATURE CITED 

Bernard. F. R. 1973. Crystalline style formation and function 

in the oyster Cras.tostren giyax (ThunberR. 119^). <>}iheli<i 

12:1.59-170. 
Brown, Stephen C. 1969. The structure and function of the 

digestive system of the mud snail Nassarim obsolettis (Say). 

Malacoloyia 9: -147-500. 
Langton. R. W. and P. A. Gabbott. 1974. The tidal rhythm of 

extracellular digestion and response to feeding in (htrea 

edulis L.Mnr. Rml 24:181-187. 
Morton. B. S. 1971. The daily rhythm of feeding and digestion 

in (Mri'a tdulis. Binl. Jaur. Linn. Sik: 3:329-:M2. 
. 197.3. A new theop,' of feeding and digestion in 

filter -feeding Lamellibranchia. Afoyacvi/oi/ia 14:63-79. 

. 197.58. The diurnal rhythm and the feeding 



responses of the Southeast Asian mangrove bivalve, Gelmna 
proxima Prime 1864 (Bivalvia: Corbiculacea). Forma et 
Futwtio 8:405-418. 



. 197.5). The seasonal variation in the feeding and 

digestive cycle of Amphibola crenatn (Martyn 1784) 
(Gastropoda: Pulmonata). Forma et Functio 8:17.5-190. 

_. 1977 The tidal rhvthm of feeding and digestion 



in the Pacific oyster, Crassiostrea gigas (Thunberg). Jour. 
Krp. Mar. Biol. Ecol. 26:135-141. 

Morton, J. E. 19.56. The tidal rhythm and action of the 
digestive system of the lamellibranch iMsaea rubra. Jour 
Mar. Biol. Ass. U. K. 35:.563-.586. 

Schaefer, C. W., Peter Milch and N. L. Ixjvin. 1968. Death 
from desiccation in the mud-snail. Sassanus ohsoletus: ef- 
fect of temperature, ne Nautilus 81: 109-1 14. 

Schaefer, C. W., N. L. Levin and Peter Milch. 1968. Death 
from desiccation in the mud-snail. NassariiLs ohsoletus: ef- 
fects of size. The NautUw^ 82:28-31. 

Scheltema. Rudolf S. 1964. Feeding habits and growth in the 
mud-snail Nassarius obsolet us. Chesapeake Sri. 5: 161 - 166. 

Stephens, G. C, M. I. Sandeen and H. M. Webb. 19.53. A per- 
sistent tidal rhj-thm of activity in the mud snail A'a.s,sa ob- 
soleta.Anat.Ker. 117:635. 



FOOD SOURCES FOR ANACHIS AVARA (COLUMBELLIDAE) 
AND A DISCUSSION OF FEEDING IN THE FAMILY 

Edward B.Hatfield' 

Rosenstiel School of Marine and Atmospheric Science 

4600 Rickenbacker Causeway 

Miami, Florida 33149 

ABSTRACT 

Lrnfjth meaavrements were made on indii'idiiah o/ Anachis avara maintnined in 
the laboratory on carrion, epihiota from neaip-asfi blades. o}yanics in the sediment, 
and on organics from a flow-through neawater system as a control. Snails grew 
52% as much on epibiota as on canion, and showed some growth with sediment or 
water column organics as their food. Epibiota are probably a significant souive of 
food for A. avara in the field. 



References regarding feeding in columbellid 
gastropods show varied and sometimes contradic- 
tory results (Puffer and Emerson 1953; Moore, 
1%1; Marcus and Marcus, 1962; Bandel, 1974). 
This paper reports differences in growth for 



' Present address: Jackson E^uarine Laboratory. University 
of New Hampshire, R.F.D. #1, Adams Point. Durham, New 
Hampshire 03824. 



Anachis avara (Say) on three separate food 
sources, and reviews the available literature on 
columbellid feeding. 

METHODS 

Two hundred and forty Anax;his avara were 
collected from a turtle grass, Thalassia 
testudinum (Konig). flat at Bear Cut, Miami, 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 41 



Florida, during June, 1975. These individuals 
were measured and placed in eight 19-liter 
aquaria with running salt water. Two replicates 
were maintained with carrion (C), turtle grass 
with its epibiota (E), and particulate organic 
matter and detritus in sediment (D), as food 
sources, with the slight supply of particulate 
organic matter in the flow-through water used as 
control (W). No attempt was made to measure 
the amount of food provided or the amount of 
organic matter entering with the running water. 
It was assumed that the 120 grass blades and the 
4 cms. of sediment in the separate pairs of 
aquaria provided the relative amounts of their 
associated foods available in the habitat. The tur- 
tle grass and sediment were changed weekly. Car- 
rion was provided twice weekly for six-hour 
periods, and all eight aquaria were cleaned 
thoroughly at weekly intervals. The length of 
each snail was measured to the nearest 0.01 mm 
with vernier calipers every fourteen days for a 
period of six weeks. Differences between mean 
sizes were tested by a two-level nested ANOVA 
at the 0.05 alpha level and by the Student- 
Newman-Keuls non-parametric test (Sokal and 
Rohlf, 1969). 

RESULTS 

Table 1 shows no difference in mean lengths of 
the snails in the eight aquaria at the beginning 
of the experiment. After 28 days, three separate 
groupings by mean size were recognizable. Snails 
which were fed carrion grew the most; those fed 
grass blade epibiota grew next best; and those fpd 
sediment organics and detritus grew the least, 
the latter being grouped with the snails from the 
control aquaria. The differences in size which oc- 
curred are shown in Figure 1. Significant results 
from this experiment are that: 1) growth oc- 
curred in all tanks, including the controls where 
the only food source was particulate organic mat- 
ter entering through the flow-through seawater 
system ; 2) snails feeding on the epibiota from the 
grass blades grew 52% of the amount that snails 
feeding on carrion did. Depending on relative 
availability of epibiota and carrion in the field, 
this latter result suggests that these epibiota are 
an important food source for .4. avara in seagrass 
habitats. 



TARLE 1. Mean iemjth (mm) «/ Anachis avara and renults of 
a Studcnt-Newman-Ki'iiU analyxif offeediiuj. Tlic fond types 
connected by each bar contain snaih of the name statistical 
mean length. 

Time 

(days) Length (mm) 



E2 
5.17 


El 
5.15 


W2 
5.10 


Wl 
4.98 


D2 
4.96 


Dl 

4.86 


C2 

4.81 


CI 
4.73 


C2 
6.85 


CI 
6.40 

CI 

8.06 

CI 

9.50 


El 
6.13 

El 
7.23 

El 
7.68 


E2 
6.03 


Dl 
5.56 


Wl 
5.27 


W2 
S.15 


D2 
5.09 


C2 
8.29 

C2 

9.61 


E2 
7.19 

E2 
7.61 


Dl 
6.06 

Wl 
5.81 


D2 
5.68 

Dl 
5.76 


Wl 
5.61 

W2 
5.27 


W2 
5.25 

D2 

* 



C = carrion; E = epibiota; D = detritus; W = organics 
from seawater (controls); * = no data; 1 & 2 = replicates of 
each food type. 



DISCUSSION 

Several food sources are available to Anachis 
avara at Bear Cut. Many of the mean 3291 
seagrass blades per m^ are encrusted with various 
kinds of epibiota (Humm, 1964; Meyers et ai, 
1965; and personal observations). These epibiota 
include polychaetes, hydroids, tunicates, sponges, 
bryoza, and protozoa, as well as diatoms, blue- 
greens and several species of red, green, and 
brown macroalgae. No attempt was made to dif- 
ferentiate between epifauna and epiflora as food 
sources for Anachis avara. Carrion, such as dead 
spider crabs, fish, and the large bivalve, Atrina 
riyida. was visibly entrapped in the sediment. 
Particulate organics and detritus were also pre- 
sent in the habitat substratum. 



10.5 





C = 


Carrion 






E = 


Epibiota 


C 


^... 


D = 


Detritus 


^^ 


■J 8.5 . 


W = 


Control 


^^ 


LENGTH 
en 


^^ 




""^ E 

D 








W 


4,5 


^'*— 





14 28 42 

TIME (days) 

FIG. \. Mean lengths (mm) of Anachis avara fur two 
replicates of each of three food types and a control. 



42 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



The amounts and availability of the different 
f(x)d sources of Anachis avara at Bear Cut prob- 
ably differ. A. avara is the only abundant 
sizeable gastropod prazer at Bear Cut, aside from 
the micromollusks, Bittium varium, Tricolia af- 
finis, and several species of Caecum. Only occa- 
sional individuals of other columbellid species or 
other gastropods such as Turbo castaneus or 
Astraea americana were collected. Therefore, 
although some overlap in food choice may exist 
between A. avara and species from other phyla, 
such as caridean shrimp, competition for the 
epibiota is not thought to be intense. The high 
productivity and continuous presence of epibiota, 
and the probable low competition for this fauna 
and flora, make this source of food highly 
available to A. avara. 

Carrion is also available to Anachvi avara, but 
it is also consumed by swimming crabs, Calli- 
nectes sapidus and Callinectes oniatu.% juvenile 
spiny lobsters, Panularus argus, stomatopods, 
several species of fish and other faunal groups. I 
placed pieces of the bivalve, Chione cancellata, in 
the habitat and witnessed several Callinectes cap- 
ture them prior to observable reaction by A. 
avara. Particulate organic matter from the sea- 
water and sediment is also available; however, 
results of the laboratory experiment suggest this 
is only a minimal source of food. 

Anachis avara probably feeds opportunistically, 
and this may be typical of many species of the 
family Columbellidae. In the laboratory-, I have 
seen Anachis avara feed on moribund Tagelus 
divims, a small gaping bivalve, but not on 
tightly-closed Tellina texana or Macoma cenna. 
Scheltema (1969) maintained Anachis avara on 
clam meat in the laboratory. Puffer and Emerson 
(1953) reported Amwhis avara semiplicata from 
an oyster reef off central Texas as a herbivore. 
Moore (1961) suggested that Anachis avara from 
Port Aransas, Texas, preys on young oysters. 
Because Anachis avara does not extend from the 
Atlantic into the Gulf of Mexico (Scheltema, 
1968; and Radwin, 1977), the species reported by 
Puffer and Emerson (1953) and Moore (1961) is 
probably Anachis semiplicata (Radwin, 1977: and 
Moore, pens. com.). However, the status of the 
western Gulf of Mexico species is not clear 
(Scheltema, 1968). Individuals of Anachis 



semiplicata from Sarasota, Florida, and of 
Anachvi avara from Bear Cut lived and spawned 
in the laboratory on a diet of clam and fish meat. 

Differences in foods reported for several col- 
umbellid species are partly the result of in- 
complete feeding investigations and secondary 
reports. Marcus and Marcus (1962) found algae in 
the gut of Columbella mercatoria. Bandel (1974) 
reported spawning for individuals of this species 
maintained in the laboratory on both algae and 
fi.sh meat. I saw capsules produced in aquaria by 
individuals of this species that had been fed clam 
and fish meat exclusively. I also saw Columbella 
rmticoides spawn in the laboratory on the same 
clam and fish meat diet. Marcus and Marcus 
also found algae in the gut of this species. 
Miller (1974) stated that most columbellids are 
attracted to dead and/or injured prey, although 
members of the genus Columbella probably eat 
primarily plant material. The conclusion from 
Marcus and Marcus (1962) that the two above 
species of Columbella are solely herbivorous is 
not correct. 

From a detailed study of the anatomy of eight 
columbellid species, Marcus and Marcus (1962) 
included that as a group the columbellids are 
general feeders. Marcus and Marcus (1962) found 
recognizable parts of polychaetes, Crustacea, and 
colonial ascidians in the alimentary tract of six 
species of columbellids. Raeihle (1969) stated that 
newly hatched Nitidella ocellata (now Mitrella 
ucellata (see Abbott, 1974)) and an unidentified 
Anachis sp. fed on crushed Mytilus edulis spat. 
Bandel (1974) reported that Nitidella laevigata 
eats Sargassum as well as meat; that Mitrella 
argus and Anachis obesa eat hydroids but also 
feed on pieces of clam and fish meat; and that six 
other columbellid species feed on fresh meat in 
the laboratory. Spight (1976) mentioned that 
some columbellids feed on freshly killed crabs, 
limpets, and chitons in the laboratory-. I have also 
maintained Mitrella ocellata Mitrella bmata, 
and Nitidella moleculina in the laboratory on 
fresh meat from several species of fish and 
bivalves. Fretter and Graham (1962) point out 
that the superfamily Buccinacea is carrion- 
feeding, rather than predatory, as its members 
have lost the accessory salivary glands and boring 
organ necessary for that activity. In general. 



Vol. 93(1) 



January 10, 1979 



THE NAUTILUS 43 



foods among the columbellids vary and it is prob- 
able that at least some species utilize varied plant 
and animal sources. 

As no analysis was made of what Tlmla.'^Kia 
epibiota or sediment organics and/or detritus 
that Anachis avara fed on during the laboratory 
experiment, it cannot be concluded whether this 
species is carnivorous or omnivorous. Leathern 
and Maurer (1975) refer to this species as a car- 
nivore, but they reach this conclusion from 
published references (Leathern, pers. com.). To my 
knowledge the results of a discrete test of 
whether Anachis avara is carnivorous or om- 
nivorous have not been published. I conclude that 
Anarchis avara can obtain nutriment from other 
than carrion, particularly by grazing epibiota off 
turtle grass blades, but also from particulate 
organics in the sediment and from the water col- 
umn. Where there is a plentiful source of food, I 
doubt that food is a limiting resource for this 
species in the seagrass flats near Miami, Florida. 

ACKNOWLEDGMENTS 

This work was completed as part of a disserta- 
tion in partial fulfillment of the requirements for 
the degree of Doctor of Philosophy at the Univer- 
sity of Miami, Miami, Florida. I would like to 
acknowledge the help of members of my commit- 
tee of which Drs. H. B. Moore and D. R. Moore 
critically read the manuscript. 

LITERATURE CITED 

Abbott. R. T. 1974. American Seashelk. Van Nostrand 

Reinhold Co., New York. 66,3 pp. 
Bandel, K. 1974. Spawning and development of some Col- 

umbellidae from the Caribbean Sea of Colombia (South 

America). The Fe/iser 16(3):271-282. 



Spetimen Shells 

Offering microscopic and miniature (to ' : inch) shells from 
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Margaret Teskey 

P. 0. Bnx 27S 

BiijPineKeii.FI -imi 



Fretter. V. and A. Graham. 1%2. Rritijih Pmxohranch 

A/(i//H,sr.s-; Their Functimml Anatomy and Eriiliigy. Ray 

S(x.'iety. London. 7.5.5 pp. 
Hiunm, H. J. 1964. Epiph>-tes of the sea grass. Vialaxsia 

trxtiidinum in Florida. Btdt. Mar. Sri. Gulf and (hrih. 

14(2):3()6-:i41. 
Leathern. W. and D. Maurer. U)7.5. The distribution and 

ecology of common marine and estuarine gastropods in the 

Delaware Bay area. Nautihi.'^ 89(3):73-79. 
Mareas, E. and E. Marcus. 1962. Studies on Columbellidae. 

Bol. Far. Filo.'t. Cien. Let. Univ. San Pmdo. 261(Zool 

21):a3.5-:»4. 
Meyers. S. P., P. A. Orpurt. J. Simms and L. L. Boral. 19&5. 

Thalassiomycetes VIL Observations on fungal infestation of 

turtle gi-ass, Thalassia testudinum Konig. Bull. Mar. Sri. 

15(3):.548-564. 
Miller, A. C. 1974 A comparison of gastropod species diversity 

and trophic structure in the rocky intertidal zone of the 

temperate and tropical west Americas. Ph.D. Diss.. Univ. of 

Oregon. 143 pp. 
Moore, D. R. 1961. The marine and brackish water Mollusca of 

the state of Mississippi. G«i/i?e.'i. Rep. l(l):l-58. 
Puffer, E. L. and W. K. Emerson. 195,3. The moUuscan com- 
munity of the oyster-reef biotope on the central Texas 

coast. Jw/r. nfPaeleo. 27(4):537-.544. 
Radwin, G. E. 1977. The family Columbellidae in the western 

Atlantic. Part Ila: The Pyreninae. The VWi:g.'r20(2):119-133. 
Raeihle, D. 1969. Egg cases of Nitidella ocellata Gmelin and 

an Anachix. Ann. Report Amer. Malaeol. t'mon. :25-26. 
Scheltema, A. H. 1968. Redescriptions of Anachis avara (Say) 

and Anachis translirata (Ravenel) with notes on some 

related species (Prosobranchia. Columbellidae). Breinora 

304:1-18. 
. 1969. Pelagic larvae of New England gastropods. 

IV. Anachis translirata and Anachis avara (Columbellidae, 
Prosobranchia). Vie et Milieu. Serie A: Biologie Marine 

20(1-A):94-104. 
Sokal. R. R. and F. J. Rohlf. 1969. Biometry W. H. Freeman 

and Co., San Francisco. 776 pp. 
Spight. T. M. 1976. Censuses of rocky shore prosobranchs from 
Washington and Costa Rica. The Veliger 18(3):309-317. 



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44 THE NAUTILUS 



January 10, 1979 



Vol. 93 (1) 



FIELD EVIDENCE THAT THE EASTERN MUD SNAIL, 

ILYANASSA OBSOLETA, 
INFLUENCES NEMATODE COMMUNITY STRUCTURE' 



Jean Ann Nichols and J. Roy Robertson 

University of Ge^irgia 

Marine Institute 

Sapelo Island, GA 31327 

ARSTRACT 

Exclusion experiment's conducted with the mud snail, Ilyanassa obsoleta (Say), in 
nematode and benthic diatom communities showed that the areas devoid of snails had 
higher densities of both benthic diatoms and Pseiidotheristid nematodes than the con- 
tiguous control area. We suggest that the increase in the diatmn-eating 
Pseudotheristus s-p. in the exclusion plot was a behavioral response to increased 
diatom densities, thus demonstrating an indirect trophic interaction between a 
moUuscan macrofaunal herbivore and a nematode member of the meiofaunal com- 
munity. 



The mud snail Uynassa obsoleta (Say) is an 
ubiquitous organism in the intertidal region, 
ranging from the Gulf of St. Lawrence to north- 
eastern Florida on the east coast of North 
America. It is an omnivorous depositfeeder, ap- 
parently subsisting almost entirely on ingested 
sand and mud and associated organisms (Brown, 
1969). The animal has been the subject of many 
experimental and descriptive studies, but little 
work has been concerned with the influence of /. 
obsoleta on biological components of its environ- 
ment. As a portion of a project to develop field 
methods for analysis of possible trophic links be- 
tween faunal groups, we initiated a series of ex- 
periments on an intertidal salt marsh creekbank 
at Sapelo Island, Georgia. Results from these ex- 
periments indicate that when the eastern mud 
snail Hyanai^sa obsoleta (Say) is excluded from an 
area, meiofaunal nematode populations respond 
to increases in diatom population and that this 
response is most probably a result of feeding 
behavior. 

Wetzel (1976) demonstrated that Ilyanassa ob- 
soleta (Say) can ingest and assimilate benthic 
diatoms. In addition. Pace (1977) has shown that 
if /. obsoleta (Say) is excluded from an area of 



' Contribution No. 379 from the University of Georgia Marine 
Institute. 



the intertidal creekbank in the salt marsh, both 
chlorophyll a and ATP concentrations in the top 
centimeter of sediment show significant increases 
within twenty-four hours. After five days the 
concentrations of these substances increased 
significantly within the 2-5 cm layer of sediment. 
However, he did not determine the actual cause 
of these increases. Since up to 90% of total sedi- 
ment ATP can be attributed to nematodes 
(Sikora et al.. 1977), it is possible that the dif- 
ference in ATP concentrations observed by Pace 
(1977) reflected significant changes in the 
nematode community. We utilized similar e.xclu- 
sion techniques to obtain diatom blooms with the 
intent of studying numbers of individuals rather 
than lumped sums of chlorophyll a and ATP. 

The study area was the same as used by Pace 
(1977). The intertidal sediment is 80% silt-clay. In 
July, the time of this e.xperiment, the average 
density of /. obsoleta (Say) is 1500 m ^ A one 
meter square area was enclosed with ' 4" (0.635 
cm) hardware cloth 50 cm high and extending 3 
cm into the sediment. Snails were removed from 
the enclosed area. One square meter contiguous 
with the experimental area was used as a control. 
Just after the water receded from the area, 3 cm' 
pieces of lens paper (double thickness) were 
placed in four randomly selected areas in both 



Vol. 93 (1) 



January 10, 1979 



THE NAUTILUS 45 



the experimental and control areas. Small cages 
were placed around the lens paper in the control 
area to prevent disturbance by snails during col- 
lection of the algae. These cages were in place on- 
ly during collection of algae. After three hours 
the lens paper was collected and diatoms removed 
by a method similar to that of Eaton and Moss 
(1966). Briefly, lens papers were heated with 
sulfuric acid and potassium permanganate. They 
were then washed in distilled HjO by centrifug- 
ing and decanting, transferred to vials and 
brought to constant volume of 3 ml. Four sub- 
samples (2 X 10" ml) from each vial were 
counted using a hemacytometer. This method 
may overestimate numbers due to cell breakage 
and separation of valves (Eaton and Moss, 1966) 
but is necessary to determine the species com- 
position of the samples. 

A ten cc syringe was used to collect samples of 
the nematode population. It was assumed that 
nematodes near the surface of the sediment were 
more likely to be influenced by the diatom 
populations than those in deeper sediments. 
Therefore, only the top two centimeters of sedi- 
ment were collected. Three samples, collected ran- 
domly from both the experimental and control 
areas, were fixed with formaldehyde (3% V/V). 
After twenty-four hours in the formaldehyde 
solution, samples were rinsed through a 45 j/m 
mesh screen. Individuals retained on the screen 
were counted. After dehydration, glycerine slide 
mounts were prepared. 

Data presented here are from samples obtained 
on day 1 and day 5 of the experiment. On both 
days the mean number of cells/ cm^ within the ex- 
perimental area was greater than the control 
area (Table 1). ANOVA tests of mean number of 
diatom cells/ cm' indicate that there were signifi- 
cant differences between the experimental and 
control areas and between days. The significant 
interaction term is due to the fact that the in- 
crease in cell concentration from day 1 to day 5 
was greater in the experimental area than in the 
control area (Table 2.). 

The patchy distribution of nematodes prevents 
any meaningful statistical analysis of the 
numbers of organisms obtained in the samples. 
However, on day 1 the average number of 
nematodes in all samples was 100. After five days 



TABLE 1. Numbers of diatoms observed. 



Day 1 
Dav 5 



Erperimpitt(d Cimtrol 
2.93 0.67 

7.12 1.27 



Mean number of cells/an' X 10' 



the average number of individuals in the control 
area remained at 100. Average number of in- 
dividuals within the experimental area had in- 
creased to 300. 

The change in species composition between day 
1 and day 5 is of great interest. Initially, the 
nematode populations were composed of about fif- 
teen different families (several undescribed 
species are represented), principally representing 
the Enoplida and Monhysterida orders. This 
diverse distribution remained in the control area. 
On day 5, 70% of the individuals from the ex- 
perimental area were Pseudotheristus sp. This 
species represented only 19% of the population in 
the control area. The actual number of non- 
Pseudotheristus individuals remained stable in 
both the experimental and control. Thus, the in- 
crease in numbers of individuals in the ex- 
perimental area was due entirely to the presence 
of Pseudotheristus sp. 

Information on the generation time of free- 
living marine nematodes is scarce. Tietjen (1969) 
and Tietjen and Lee (1972, 1973) have reported 
minimum generation times of 22 days under op- 
timal laboratory conditions. Hopper, Fell and 
Cefalu (1973) report generation times of 1-^4 days 
to 112 days for six free-living nematode species 
cultured from decaying mangrove {Rhizophora 
mangle) leaves. Since the first egg cleavage re- 
quires from six to thirty-five hours (Hope, 1974), 
it seems unlikely that reproduction could account 
for the increase in numbers of adult individuals 
observed during the period of five days. 

TABLE 2. Analysis of variance of diatom numbers. 





.SN df 


)hs F 


p 


Treatment 


406.4.5 .3 






cage 


26:3.12 1 


263.12 47.92 


<.001 


days 


91.93 1 


91.93 16.65 


<.005 


interaction 


.51.41 1 


51.41 9.38 


<.001 


Samples 


65.92 12 


5.49 





SS = sum of squares; df = degree of freedom; ms = mean 
square. 



46 THE NAUTILUS 



January 10, 1979 



Vol. 93(1) 



S^eventy-five percent of the Pfteudotheri.'^tus sp. 
contained diatoms within their guts. Individuals 
contained from two to twenty-two diatom 
frustules. In most cases chioroplasts were visible 
when the frustule was located in the anterior 
portion of the gut. but not in the posterior posi- 
tion. Diatoms were not found in the guts of any 
of the other species of nematodes in either the 
control or experimental area. 

While it is possible that the difference in 
nematode density was because predation by the 
mud snails, two lines of evidence render this in- 
terpretation unlikely: dissection of over thirty /. 
obsioleta (Say) revealed no nematodes in their 
caecae and the change in nematode density was 
entirely due to increase in the Pseudothe7i.<itvs 
sp. population. It is unlikely that /. ohsoleta (Say) 
individuals exercise any selection over the type of 
material ingested from the substrate (Brown, 
1969). Therefore, we suggest that the increase in 
Pseudotheristus sp. is a result of competitive 
release, thus demonstrating an indirect trophic 
interaction between the macrofaunal species R- 
yanassa ohsoleta (Say) and the meiofaunal species 
PsevAotheristns sp. 



LITERATURE CITED 

Brown, S. C. 1969. The structure and function of the digestive 

system of the mud snail Nassarius obsoletus (Say). 

Malacologia 9:447-498. 
Eaton, J. W., Moss, B. 1966. The estimation of numbers and 

pigment content in epipelagic algal populations. Limnol. 

Oceaniiyr. 11:584-. ^.5. 
Hope, W. D. 1974. Nematoda. In Reproduction of Marine In- 

vetiehrntes Vol. 1. (Giese. A. C. & Pearse, .1. S.. ed.) 

Academic Press. New York. pp. 391-470. 
Hopper, B. E.. Fell, J. W., and C«falu, R. C. 1973. Effect of 

temperature on life cycles of nematodes associated with the 

Mangrove (Rhizophnra mangle) Detrital System. Marine 

Bn(/(v.'/ 23:293-296. 
Pace. M. L. 1977. The effect of macroconsumer grazing on the 

benthic microbial community of a salt marsh mudflat. MJ^. 

Tliesis. University of Georgia. Athens, Georgia. 80 pp. 
Sikora, J. P., Sikora, W. B.. Erkenbrecher. C. W., and Coull, 

B. C. 1977. Significance of ATP. carbon, and caloric content 

of meiobenthic nematodes in partitioning benthic biomass. 

Marine Binlogy 44:7-14. 
Tietjen. .1. H. 1969. The ecology of shallow water meiofauna in 

two New England estuaries. Ckcohiyia 2:2.51-291. 
Tietjen, J. H., Lee. J. J. 1972. Life cycles of marine nematodes. 

Oecoloyid 10:167-176. 
. 1973. Life history and feeding habits of the 

marine nematode, Chromaiiora macrolaimoidex Steiner. 

Oecologia 12:303-314. 
Wetzel. R. L. 1976. Carbon resources of a benthic salt marsh 

invertebrate, Nassarius obsoletus Say (Mollusca: 

Na.s.sariidae). In Estuarine Processes. Vol. 11 (Wiley, M., 

ed.) Academic Press. New York. pp. 293-.308. 




LIVING MARINE 

MOLLUSCS 



ECOLOGY 

REPRODUCTION 

ANATOMY 



C, M. Yonge and T. E. Thompson 

An Understandable Biology Text 

The first modem book on the biology of marine mollusks 
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and illustrated that the legions of amateur conchologists 
will readily absorb its wealth of information"—/?. Tucker 
Abbott. Ph.D. 




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MOLLUSK VOUCHER SPECIMENS 



It is becoming increasingly important for 
future research purposes that an identified sam- 
pling of species mentioned in publications be 
deposited in a permanent, accessible museum 
specializing in mollusks. This is particularly 
true of mollusks used in physiological, medical, 
parasitological, ecological, and experimental 
projects. 



Several museums of natural history have ex- 
tensive modern facilities and equipment for the 
housing and curating of voucher specimens. 
Material should be accompanied by the identifica- 
tion, locality data and its bibliographic reference. 
There is no charge for this permanent curating 
service, and catalog numbers, if desired, will be 
sent to authors prior to publication. 



APRIL 23, 1979 

(April and July numbers combined) 



THE 



NAUTILUS 







ISSN 0028-1344 
Vol. 93 

No9. 2 and 3 



A quarterly 

devoted to 

malacology and 

the interests of 

conchologists 



Founded 1889 bv Henry A. Pilsbr>'. Continued by H. Burrington Baker. 
Editor-in-Chief: R. Tucker Abbott 



EDITORIAL COMMITTEE 



CONSULTING EDITORS 



Dr. Arthur H. Qarke, Jr. 

Division of Mollusks 

National Museum of Natural History 

Washington, D.C. 20560 

Dr. William J. Clench 
Curator Emeritus 
Museum of Comparative Zoology 
Cambridge, Mass. 02138 

Dr. William K. Emerson 
Department of Living Invertebrates 
The American Museum of Natural History 
New York. New York 10024 

Mr. Morris K. Jacobson 

Department of Living Invertebrates 

The American Museum of Natural History 

New York, New York 10024 

Dr. Aurele La Rocque 
Department of Geology 
The Ohio State University 
Columbus, Ohio 43210 

Dr. James H. McLean 
Los Angeles County Museum of Natural History 
900 Exposition Boulevard 
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Dr. Arthur S. Merrill 
Woods Hole Biological Laboratory 
National Marine Fisheries Sei-vice 
Woods Hole, Massachusetts 02543 



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Division of Marine Geolog>' 
School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, Florida 33149 

Dr. Joseph Rosewater 
Division of Mollusks 
U. S. National Museum 
Washington, D.C. 20560 

Dr. G. Alan Solem 
Department of Invertebrates 
Field Museum of Natural History 
Chicago, Illinois 60605 

Dr. David H. Stansbery 
Museum of Zoology 
The Ohio State University 
Columbus, Ohio 43210 

Dr. Ruth D. Turner 
Department of Mollusks 
Museum of Comparative Zoology 
Cambridge. Mass. 02138 

Dr. Gilbert L. Voss 
Division of Biology 

School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, Florida 33149 

Dr. Charles B. Wurtz 
3220 Penn Street 
Philadelphia, Pennsylvania 19129 



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Dr. R. Tucker Abbott 
American Malacologists, Inc. 
Box 4208, Greenville, Delaware 19807 

Mrs. Cecelia W. Abbott 

Business and Subscription Manager 

P.O. Box 4208 

Greenville, Delaware 19807 



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THE 

NAUTILUS 

Volume 93, numbers 2-3 — April 23, 1979 

ISSN 0028-1344 

CONTENTS 

Bernadine Barker Baker 

A Tribute Upon her Retirement '^ 

Melbourne R. Carriker , , . ,o, . \n 

Ultrastructural Effect of Cleaning MoUuscan Shell with Sodium Hypochlorite (Clorox) 4/ 

David R. Lindberg 

Variations in the Limpet. CoUiseUa ochracea, 

and the Distribution oiNatoacmea testudinalis (Acmaeidae) ^ 

HansBertsch t, /i^ ^ r> c \ k^ 

Tropical Faunal AffinitiesofOpisthobranchsft-om the PanamicProvmce (Eastern Pacific) i>i 

Melissa A. Barbour 

A Note on the Distribution and Food Preference of Cadlina laems 

(Nudibranchia: Chromodoridae) 

Dorothea S. Franzen tt • jo <. kq 

Catinella paralleled A New Succinidae (Pulmonata) from Midwestern United States ^^ 

Billy G. Isom, Sally D. Dennis and Charles Gooch 

Rediscovery of Some Pleurocerids (Gastropoda) Near Muscle Shoals, 

Tennessee River, Alabama 

Amy Shrader Van Devender 

A New Vertkjii (Pulmonata: Pupillidae) from the Ozarkian Uplift 

Alton C. Boozer and P. E. Mirkes 

Observations on the Fingernail C\&mjiusculium partumeivm (Pisidiidae), 

and its Association with the Introduced Asiatic Clam, Corbiculafluminea '-i 

Billy G. Isom, Charles Gooch and Sally D. Dennis 

Rediscovery of a Presumed Extinct River Mussel, Dijf^nnmia sulcata (Unionidae) »4 

Terrence M. Gosliner , j j ^ qr 

A Review of the Systematics of CylichneUa Gabb (Opisthobranchia: Scaphandridae) "•'^ 

Robert S. Prezant „„ 

Shell Spinules of the Bivalve, L?/onsia hyalina ^^ 

William J. Clench 

A Biography of Andrew Garrett, Early Naturalist of Polynesia: Part 2: 

Catalogue of Molluscan Species and Bibliography 

Hugh J. Michael-Tapping , , , ino 

The Caecidae (Gastropoda: Rissoacea) of Water Island, U.S. Virgin Islands, with a new species W6 

Donald R. Moore and Mabel Fentress Miller 

Discovery of Living Bivalved Gastropods in the Florida Keys i"" 



News 



56, 92 Recent Death (Teramachi) 83 




BERNADINE BARKER BAKER 
Retiring Business Manager of The Nautilus 

For nearly half a century Mrs. H. Burrington 
Baker, known to her friends as Bunny, has either 
collected shells, written about shells, or has been 
actively assisting scientists and editors in their 
malacological endeavors. S(K)n after she married 
the zoologist, and co-editor of The Nautilus, H. 
B. Baker in 1941, Bunny began proofing manu- 
scripts and keeping the subscription records. 
Throughout the following 38 yeai-s her voluntary 
assistance has made the continuation of Tlic 
NaiitUii.<; possible. 

Mrs. Baker has been the fourth Business and 
Subscription Manager in the 93-year life of this 
journal. The first was its co-founder, William D. 
Averell (1853-1928) of Mt. Airy, Philadelphia, 
who served for the first three volumes from 1886 
to 1890. The second was Charles W. Johnson 
(1863-1932) of Philadelphia and later of Boston 
who served from 1890 until his death in 1932 over 
a period of 42 volumes. The third was Horace 
Burrington Baker (1889-1971), of Havertowm, Pa., 
who served from 1932 to 1958 when he then be- 
came senior editor. It was at this time during the 
71st volume that Bunny became the fourth Busi- 



ness Manager and has served in that capacity for 
20 years. Although retiring now, and still very 
active in the affairs of the Delaware County 
Memorial Hospital, Bunny is in excellent health 
and will continue to give sage advice and guid- 
ance to The Nautilus. 

Bernadine Barker Baker was bom October 1, 
1906, in Quincy, Massachusetts, and received her 
A. B. degree in 1928 from Radcliffe College in 
Cambridge, Mass. She taught at Burdett College 
for three years, then was Financial Secretar>' at 
the Children's Museum in Boston where she first 
became interested in shells. With her co-worker 
Mildred Seymour (later MacCoy), Bunny ventur- 
ed on an expedition with Harvard scientists in 
1934 to the Everglades of Florida. 

Mi-s. Baker is a Life Member of the American 
Malacological Union, having joined as early as 
1934, and served as its Treasurer from 1966 to 
1972. She was Secretary of the Boston Mala- 
cological Club from 1935 to 1941, and is a charter 
member of both the Philadelphia and Wilmington 
Shell Clubs. Her interests have been mainly in 
marine mollusks. Her collection was donated to 
the Museum of Comparative Zoology, at Harvard, 
a few years ago. She published two scientific ar- 
ticles in The Nautilus, one in 1950 on the marine 
mollusks of St. Petersburg, and the other in 1951 
on "Interesting Shells from the Delmarva Penin- 
sula." 

Bunny was engaged to her future husband at 
the 1941 A. M. U. meetings in Rockland. Maine, 
and appropriately they spent their hone.vmoon on 
shell-rich Sanibel Island, Florida. Until "H. B.'s" 
death in 1971, she assisted in 77!* Nautilus mat- 
ters, and raised two daughters, Elizabeth, now 
Mrs. Warren Brandkamp, and Abigail, now Mrs. 
John Kraljevich. She has four grandchildren. Her 
husband immortalized her name in malacological 
literature in 1942 by naming a new genus and 
new species of Mexican land snail, Bunnya ber- 
nadinae. For 17 years Bunny has been a vol- 
unteer worker at the Delaware County Memorial 
Hospital (see Our Family, vol. 5, no. 10, Aug. 
1977), and she continues to assist in their Gift 
Shop. Among her hobbies are hooking rugs and 
collecting miniature bunnies. Bunny may still be 
reached by her friends at 11 Chelten Road, 
Havertown, PA, 19083. (R. T. Abbott). 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 47 



ULTRASTRUCTURAL EFFECT OF CLEANING MOLLUSCAN SHELL 
WITH SODIUM HYPOCHLORITE (CLOROX) 

Melbourne R. Carriker 

College of Marine Studies 
University of Delaware 
Lewes, Delaware 19958 

ABSTRACT 

The corrosive effect of sodium hypochlorite (commercial clorox) on the ultra- 
structure of the (i)yanir components of the shell of the bivalve Mytilus edulis 
Linne is described, and the detrimental results are related to cleaning of mollus- 
can shells preparatory to storage in collections. 



INTRODUCTION 

Sodium hypochlorite solutions have been em- 
ployed routinely by shell collectors for some time 
to remove algal and other organic grovrths from 
the exterior of molluscan shells in preparation 
for storing them in collections (Abbott, 1954; 
Bales, 1974). 

Commercial clorox, 5.25% sodium hypochlorite, 
available at most grocery stores, does not 
disfigure the mineral portions of shells, but does 
dissolve the organic matter. Soft molluscan and 
other tissues are dissolved rapidly (in a few 
seconds), while tough tissues, like molluscan 
periostracum and ligament, take considerably 
longer. Hamilton (1969), for example, was forced 
to treat valves of tellinid bivalves for as long as 
30 to 60 days to completely remove the perios- 
tracum. Differential dissolution of organic matrix 
of shell by sodium hypochlorite has been used to 
good advantage by such investigators as Towe 
and Hamilton (1968), Mutvei (1970), and Carriker 
(1978) in the study of the fine structure of the 
units of molluscan shell. 

The purpose of this note is to describe the ef- 
fect of clorox on molluscan shell at ultrastruc- 
tural magnifications, and to discuss these obser- 
vations with reference to the procedures em- 
ployed by shell collectors in cleaning shells. 

METHODS 

Shells of the bivalve Mytilus edulis Linne were 
employed for testing the effect of solutions of 
sodium hypochlorite. Rapidly growing specimens, 
approximately 6 cm in length, were collected in 



the vicinity of Woods Hole, Massachusetts. 
Valves, freshly cleaned of meats and washed in 
tap water, were shattered with a blow from a 
hammer. Pieces of shell, about 4 to 8 mm in long- 
est dimension, were selected from the thick mid- 
dle region of the valves. All major layers of shell 
were represented in each fragment: the exterior 
organic periostracum, the calcific prismatic 
stratum, and the aragonitic nacreous layer next 
to the mantle (see Carriker, 1978, for review of 
the ultrastructure of the shell of this bivalve). 

Several pieces of shell were placed in each of 
three small beakers, each beaker containing 30 ml 
of full strength commercial clorox (5.25% sodium 
hypochlorite). Beakers were covered, gently swirled 
by hand from time to time, and maintained 
at room temperature in a laboratory normal- 
ly lighted with overhead fluorescent illumina- 
tion. Shell pieces in beaker a) were immersed in 
clorox for 10 minutes, those in beaker b) for 30 
minutes, and those in beaker c) for 40 hours. At 
the end of these periods, shell fragments were 
rinsed several times in cold tap water, drained on 
absorbent paper, and dried in a stream of warm 
air. Representative pieces from the three beakers 
were then mounted on 1 cm brass stubs with 
silver paint, dried in an oven at 60°C for a day, 
coated with gold in vacuum, and examined with a 
scanning electron microscope, using magnifica- 
tions of 2000 to 6000 times at a voltage of 15 k\'. 

RESULTS 

Ridges on the untreated surface of the perios- 
tracum of Mytilus edulis ranged in width from 



48 THE NAUTILUS 



April Z% 1979 



Vol. 93 (2-3) 



1.4 to 2 fiin (Fig. 1). This corrugated pattern was 
completely destroyed by treatment with clorox 
for 40 hours (Fig. 2), leaving cracked, buckled 
shreds of periostracum draping over the tops of 
tubercles of the thin mo-saicostracal layer (Car- 
riker, 1979) which binds the periostracum to the 
prismatic layer of the shell. Immersion of perios- 
tracum in clorox for shorter periods resulted in 
progressively less erosion of its surface. 

Treatment of fractured surfaces of the 
prismatic layer of shell with clorox for 40 hours 
(Fig. 5) caused complete removal of the inter- 
pristmatic organic matrix (conchiolin) which sur- 
rounds each individual prism as an envelope and 
binds adjacent prisms to each other (compare 
with Fig. 3; prisms roughly 1 to 3 fim in major 
cross sectional dimension). The treatment also 




FIG. 1. Exterior of periostracum i/Mytilus edulis near edge 
of valve illustrating ntrrmal, smonthly corrugated, untreated 
surface. Scanning electron micrograph. Scale bar = 2 \im. 
2, Exterior of periostracum after treatment with clorox for JfO 
hours. Periostracum was partially dvisolved. and as it dried, 
cracked atul warped. Scanning electron micrograph. Scale bar 
— S fim. 3, Normal untreated fractured surface of prismatic 
layer of shell showing broken erids and .'ddes of indicidual. 
closely fitting, anvil-shaped prisms. Scanning electron 
micrograph. Scale bar = 2 yan. 4, Fractured surface of 
prismatic layer of shell treated with clorox for 10 minutes. 
Most of interprismatic organic envelope uvs removed from 
each pri.'sm exposing pattern of mineral crystals beneath. 
Scanning electron micrograph. Scale bar = 2ym. 



etched some of the intraprismatic organic matrix 
from the mineral crj'stals within the prisms, 
revealing the jagged edges of what appeared like 
mineral platelets. Treatment with clorox for 10 
minutes (Fig. 4) resulted in the removal of only 
part of the interprismatic organic matrix. 

Exposure of the mantle surface of the nacre to 
clorox for 40 hours resulted in dissolution of the 
organic matrix which surrounds individual 
lamellae and cements them to each other (Fig. 7, 
compare with Fig. 6; lamellae roughly 5 to 10 (jm 
in longest dimension). Removal of the matrix 
created a pattern of polygonal figures illustrated 
in the several terraces of lamellae exposed in 
Figure 7. A threefold enlargement of Figure 7 
(Fig. 8) showed further that the clorox also 
solubilized some of the intracrystalline organic 
matrix within the lamellae, exposing what ap- 
peared like internal lath shaped substructures. 

DISCUSSION 

As other workers have discovered (Carriker, 
197S. Hamilton. 1969; Mutvei, 1970; Towe and 
Hamilton. 1968). clorox is a highly efficient 
solubilizer of molluscan organic materials. Ex- 
cessive use of full strength clorox in the cleaning 
of shells, however, can alter the ultrastructural 
nature of the shell surface, whereas when em- 
ployed with discretion, the chemical is extremely 
useful in cleaning periostracal and ligamental 
surfaces of molluscan shells. Unpublished obser- 
vations and the published work of others (Abbott, 
1964: Bales, 1974) demonstrated that it is dif- 
ficult to prescribe a given concentration or time 
for the use of clorox in cleaning the exterior 
surface of a particular species of shell. The age of 
the shell and previous exposure of the surface to 
weathering and to microbiological action are fac- 
tors which increase the vulnerability of the sur- 
face to dissolution. Each specimen must thus be 
treated individually, and application of the 
chemical must be made initially for a brief 
period of time. For fragile specimens it is impor- 
tant to use clorox diluted five to twenty or more 
times with tap water. S. E. Siddall and R. A. 
Lutz (personal communication), for example, em- 
ploy 2% alkalized (pH 9) clorox to dissolve the 
ligament of mussel larvae when examining the 



Vol. 93 (2-3) 



Api'il 23. 1979 



THE NAUTILUS 49 




FIG. 5. Fractured surface of prismatic layer of shell treated 
with clorox for iO hours. Interprismatic and some of in- 
traprismatic organic matrix was solvbilized, leaving con- 
spiawus spaces among prism ends. Scanniitg electron 
micrograph. Scale bar = 2 yim. 6, Normal, untreated, oblique, 
fractured surface of nacreous layer of shell showing teiraces 
of brick-shaped lamellae. Scanning electron micrograph. Scale 
bar = 2 fim. 7, Surface of nacreous layer of shell facing man- 
tle treated uith clorox for iO hours. Organic matrix between 
adjacent lamellae was dissolved resulting in pattern of 
polygonal figures. Scanning electron micrograph. Scale bar = 
6 \m. 8, Same surface as in Fig. 7 magnified three times 
more. Dissolution of superficial organic matrix within 
lamellae revealed substructure of lamellae. Scanning electron 
micrograph. Scale bar = iftm. 

hinge structure. After initial immersion in 
clorox, careful rinsing in tap water, and drying, 
the surface of the specimen should be examined 
for effectiveness of removal of organic growths 
and for possible loss of sheen and color resulting 
from chemical deterioration of the surface. 
Guided by frequent visual examinations (prefer- 
ably under a binocular microscope especially for 
small fragile specimens), the shell preparator can 
generally safely employ the required number of 
immersions in clorox to remove extraneous or- 
ganic materials without objectionably altering 
the surface of the periostracum and ligament. 

The organic matrix of the nacreous inner sur- 
face of valves, however, is much more vulnerable 
to dissolution by clorox than periostracum and 



ligament (see Fig. 7, 8). With the exception of 
fragments of flesh clinging to the muscle scars 
(myostracum), the nacreous surface is usually 
clean in freshly opened molluscs. It is thus 
necessary only to dissolve the organic matter on 
myostracal areas. This can be done without 
harming the nacre to any extent by carefully 
"applying" clorox only over the myostracal sur- 
faces under a binocular microscope, observing the 
same precautions given in the previous paragraph 
for periostracal and ligamental surfaces. 

Malacologists and conchologists often soak 
freshly collected shells in tap or seawater for a 
time to allow removal pf muscle tissue from the 
myostraca by autolysis and bacterial decomposi- 
tion. This treatment is effective in removing 
tissues, but caution must be observed as the 
treatment may also disfigure the nacreous sur- 
face as a result of the accumulation of acids in 
the water. K water must be used, it is safer to 
employ seawater because it possesses a con- 
siderably greater buffering capacity than does 
freshwater. 

The observations reported in this paper suggest 
that caution should be exercised against over ex- 
posure to clorox in cleaning shells especially for 
permanent storage in study collections. 

ACKNOWLEDGMENTS 

Thanks are extended to Virginia Peters for col- 
laboration in the scanning electron microscopy, to 
W'alter S. Kay for preparing the final prints for 
publication and to R. Tucker Abbott for helpful 
comments on the manuscript. University of 
Delaware, College of Marine Studies Contribution 
Number 123. 

LITERATURE CITED 

Abbott, R. T. 1954. American Seashells. D. Van Nostrand Co., 

Inc.. Princeton. N. J. .541 pp. 
Bales, B. R. 1974. Cleaning marine shells, in M. K. Jacobson. 

Ed., How to study and collect shells. Amer. Malacological 

Union, pp. 12-16. 
Carriker. M. R. 1977. Ultrastructural evidence that gastropods 

swallow shell rasped during hole boring. Biological Bulletin 

152: 325-336. 
. 1978. Ultrastructural analysis of dissolution of 

shell of the bivalve Mytilus edulis by the accessory boring 

organ of the gastropod Urosalpinx cinera. Marine Biology 

48: 105-134. 



50 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



1979. L'ltrastructure of the mosaicostracal layer of 

the shell of the bivalve Mylilus edulis. (Submitted to The 
Veliyer). In pres.s. vol. 21. no. 4. 

Hamilton, G. H. 1969. The taxonomic significance and 
theoretical origin of surface patterns on a newly discovered 
bivalve shell layer, the mosaicostracum. The Veliger 11: 
185-194. 



Mutvei, H. 1970. Ultrastructure of the mineral and organic 
components of molluscan nacreous layers. BiominTulizatum 
Res. Rept. 2: 48-74. 

Tnwe, K. M.. G. H. Hamilton. 1968. Ultrastructure and infer- 
red calcification of the mature and developing nacre in 
bivalve mollusks.C<i/r. Tiss. Res. 1: 306-318. 



VARIATIONS IN THE LIMPET, COLUSELLA OCHRACEA AND THE 

NORTHEASTERN PACIFIC 
DISTRIBUTION OF NOTOACMEA TESTUDINALIS (ACMAEIDAE) 

David R. Lindberg 

Department of Invertebrate Zoology 

California Academy of Sciences 

San Francisco, California 94118 U.S.A. 



In August, 1975, I collected a series of small 
limpets, less than 10 mm in length, from the 
shells of the abalone, Haliotis mfeacens Swainson, 
1822, at a depth of 8 m off Kruse Ranch, Men- 
docino County, California (38°35'N). My initial ef- 
forts to identify the specimens using shell 
characters failed, so I examined radulae from 
several of the specimens. Radulae from other 
small limpets which had been obtained from 
shells of Tegula pulligo (Gmelin, 1791), collected 
in Monterey Bay, California (36°36'N), had 
previously been prepared. When compared to 
those of the Kruse Ranch specimens, the radulae 
proved to be very similar, although the shells of 
the two groups of specimens differed markedly in 
coloration and morphology-. 

As additional material was examined, rudular 
characters initially thought to be unique to these 
two sets of specimens were also found to be pre- 
sent in CoUviella ochracea (Ball, 1871). I now 
consider the limpets from H. nifescens and T. 
pulligo to be previously unreported forms of C. 
ochracea. 

Subsequent to this, I encountered problems in 
attempting to establish the most northern dis- 
tributional record for C ochracea. Specimens 
identified as C. ochracea from western Alaska 



were not similar to southern specimens. After ex- 
tensive examination and comparisons, these spec- 
imens were recognized as Notdacmeo testudinalis 
(Muller, 1776), the presence of which in the east- 
ern Pacific has been the subject of controversy. 

This paper discusses and figures the various 
forms of C. ochracea and contains notes on the 
natural history of this species. Also included is a 
review of the presence of N. testudinalis in the 
eastern Pacific, with a discussion of its similari- 
ties to, and differences from, C. ochracea. 

Abbreviations used in the text : 

CAS - California Academy of Sciences, San 

Francisco, California. 

CASG - Department of Geology, Cal. Acad. 

Sciences. 

CASIZ - Department of Invertebrate Zoology, 

Cal. Acad. Sciences. 

LACM - Los Angeles County Museum of 

Natural History, Los Angeles, California, De- 
partment of Malacology. 

Collisella ochracea 

Collisella ochracea is a little-known eastern 
Pacific species. Dall (1871: 249) described it from 
Monterey, California, as a variety of Acmaea 
patina Rathke, 1833 [now Notoacmea scutum 
(Riithke, 1833)], and it was treated as such by 



Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 51 



Dall (1879: 1914; 1921), Pilsbry (1891), and 
Oldroyd (1927). A. R. Grant (1933) was the first 
worker to recognize C. ochracea as a distinct 
species and in a later thesis (Grant, 1938) correct- 
ly placed Acmaea peramabilis Dall, 1872, in 
synonymy. Observations by Grant (1938) of the 
radula of C. (xhracea further demonstrated its 
distinctness. The radular strap was found to bear 
vestigial, marginal teeth (uncini), the presence of 
which assigned C. ochracea to the genus Callisella 
rather than to Notoacmea. the genus to which A'. 
scutum belongs. Grant's treatment of C. ochracea 
was followed by the majority of subsequent 
workers, including Keen (1937), Burch (1946), 
Smith and Gordon (1948), Light, et al. (1955), 
Fritchman (1961), McLean (1966, 1969). and 
Carlton and Roth (1975). However, as recently as 
1974, C. ochracea has again been erroneously 
listed as a variety of A^. scutum (Abbott, 1974: 
32). 

In 1945 and 1946 Avery Ransome (Grant) Test 
published parts of her 1933 and 1938 theses. In 
the first paper the ecology of C. ochracea was 
discussed in a single paragraph in which she 
stated that the limpet occurs in the lower inter- 
tidal zone on rocks that are largely bare of 
macroscopic algae, appearing to be limited to this 
habitat by food (microscopic algae), the lack of 
competition, and permanent submergence. In the 
later paper (Test, 1946), C. ochracea was reported 
to be related to Collisella pelta (Rathke, 1833) 
based on a study of the radular characters. My 
own observations do not support this relationship 
nor is another evident at this time. Yonge (1962) 
included the species in his study of mantle cavity 
currents in acmaeids. McLean (1969: 17) reported 
that C. ochracea is one of the few acmaeid species 
occurring subtidally. McLean (loc. cit.) was also 
the first worker to refer to C. ochracea as being a 
common species. The range of C. ochracea is Cap- 
tain's Bay, Unalaska Island. Alaska (53°03'N) to 
Isla Cedros. Baja California, Mexico (28°12'N). 



The Forms of Collisella ochracea 
Collisella ochracea is an eurytopic, polyt>-pic 
species. It occurs on several different substrata 
and has shell color patterns and morphology that 



vary with the substratum occupied. One form oc- 
curs on the shells of trochid gastropods. A second 
variation occurs on encrusting coralline algae and 
two other forms occur in the low int«rtidal and 
subtidal zones. Only these last two were recog- 
nized and described by Grant (1933: 111). 

Although each form is described separately be- 
low, several general characters are present on all 
specimens. The sculpture of C. ochracea consists 
of fine, non-bifurcating riblets. The riblets are 
consistently straight and evenly spaced. The aper- 
ture of C. ochracea may vary from circular (Fig. 
2) to elongate (Fig. 4). 

Solid and Tessellate Forms (Figs. 1-2) 

Description: Shell of low to medium profile; 
apex in anterior third of shell length. Anterior 
and lateral slopes straight, posterior slope slight- 
ly convex. Solid form pale yellow to rose red. 
Tessellate form brown to gray, with symmetrical 
white markings, pattern finer at apex than at 
edge. White markings sometimes drawn out into 
bars at edge. Internal margin darker than in- 
termediate or apical areas, sometimes streaked 
with white corresponding to external pattern. In- 
termediate and apical areas may be suffused with 
blue. Internal stain, when present in solid form, 
not covering apical area. 

Remarks: As previously stated these two forms 
have been recognized since 1933 and they occur 
on smooth, bare rocks and reefs in the low 
intertidal and subtidal areas. McLean (1966: 
77) stated that specimens are common to depths 
of 9 m, but are seldom collected below this. 



Coralline Form (Fig. 3) 

Description: Shell of low to medium profile: 
apex in anterior third of shell length. Anterior 
slope concave; posterior slope convex; lateral 
slopes straight. Aperture anteriorly narrowed. 
External color pattern of brown to red coalescing 
markings on a white background; pattern at apex 
finer than at edge. Apex erodes to white. Internal 
margin white, with markings corresponding to 
pattern at external edge; internal stain, when 
present, not extending into apical area. Shell 
translucent. 



52 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



Remarks: This form occurs on intertidal and 
subtidal substrata encrusted with coralline algae 
of the genus Lithothamnion. including rocks, 
boulders, and the shells of H. rufescens. The con- 
cave anterior slope of this form distinguishes it 
from the other forms of this species. A form of 
Collisella pelta is also found on such surfaces, but 
it is readily distinguished from C. uchracea by its 
lack of fine riblets. 

Epizoic Form (Fig. 4) 

Descriptidn: Shell of medium profile; apex in 
anterior quarter of shell length. Anterior and 
lateral slopes straight; posterior slope slightly 
convex. Aperture elongate; lateral edges parallel. 
External color tan to reddish brown, generally 
mottled with white or with white markings. Solid 
forms occur. Apex erodes to white. Internal 
margin dark, with or without white markings 
corresponding to the external pattern which is 
visible through shell. Generally lacking internal 
stain. 

Remarks: This form occurs on the trochid 
gastropods Tegula brunnea (Philippi, 1848), 
Tegula montereyi (Kiener, 1850), and Tegula 
pidligo (Gmelin, 1791). The majority of my 
specimens have been collected from T. pulligo in 
the Monterey Bay area. This form of C. ochracea 
has been found on T. brunnea and T. montereyi 
in San Mateo County, California, and a single 
specimen of it was found at Bodega Bay, Marin 
County, California, on T. brunnea. Trochid 
gastropods are commonly utilized as substrata by 
acmaeid limpets. Cnllisella asmi (Middendorff, 
1847) was considered to be the only epizoic limpet 



on Tegula funebralis (A. Adams, 1855). However, 
McLean (1966: 80) reported that Collisella 
strigatella (Carpenter, 1846) was also abundant 
on T funebralis in the Monterey area, and 
Brewer (1975) reported six additional species of 
acmaeid limpets on T. funebralis. T. funebralis is 
a mid-intertidal species, and the limpets which 
occur on it are also found in the same intertidal 
zone. All three species of Tegula on which C. 
ochracea has been found are low intertidal and 
offshore kelp bed species (Carlton and Roth, 1975: 
502-503) which corresponds to the habitat of C. 
ochracea. 

Laminaria Form 

After the manuscript was submitted to the edi- 
tor a fifth form of Collisella ochracea was brought 
to my attention by M. G. Kellogg, Moss Landing 
Marine Laboratories, Moss Landing, CA. This ad- 
ditional form occurs on the stipes of the brown 
algae Laminaria dentigera and Pterygophora 
califomica; both algae are typical habitats of Col- 
lisella instabilis (Gould, 1846). Both C. instabilis 
and the C. ochracea form have similar gross shell 
morphologies (i.e. elevated anterior and posterior 
shell margins), but differ in shell markings and 
sculpture. The C. ochracea form is brown with 
white markings similar to those of the tessellated 
form described above. Collisella instabilis is also 
brown but lacks the white markings although the 
apical area typically erodes to white. The 
sculpture of the C. ochracea form is as described 
above, with straight, raised riblets. The sculpture 
of C. in.'^tabilis consists of broadly-spaced grooves 
giving the appearance of obscure, flat ribs. 



Figures 1-10 (see opposite page) 

All figure.^ actual xue unless otherwise noted. 

FIGS. 1-10. 1-4. Collisella ochracea (Dull). 1, Tes-sellate form. California: San Mateo County: Pillar Point. CASIZ No. 
0031,19. 2, Solid fiinn. California: Mendocino County: Little River, .5871? CASCi Type Collection: 3, Coralline form. California: San 
Mateo County. Ano Nucvo Pirint. CASIZ No. 0OS:i96. X 2. 4, Epizoic form. California: Monterey C(mnty. San .Jme Creek Beach, on 
Tegula pulligo (Gmelin). CASIZ No. 00.1:190. X 2 5-6. Raduia i;/' Collisella ochracea (Datl). California: Mendocino County: Kruse 
Ranch, CASIZ No. 00;lil8, X 250. 5, Radular tooth ronfiyuration, FLT = fiist lateral tooth: SLT = .'<econd lateral tooth: TI.T = 
third lateral tooth, U = uncinus. 6, Brts-a/ plalc ntoriiholoyy: FLP = first lateml plate: SLP = second lateral plate: TI.P — third 
lateral plate: VP = ventral plate: AP = anterior pivcess: AS — anterior .future. 7. Collisella ochracea (Dall). California: Santa 
Cruz Cmtnty: Soqnet Point, CASIZ No. 00:1:19:1. Note shell color pattern change at apex. Enlargement X 7. &. Notoacmea 
testudinalis (M'dler). 8A, Ataxka: Prittilof Islandi. St. Paid Island. .58716 CAS(! Type Collection: 8B, Alaska: Kenai Peninsula: 
Kachcmak Hay. Cohen Island. lACM No. 7.1-20. 9-10. Raduia u/Notoacmea testudinalis (M'dler). Alaska: Prihilof Island.^. St. Paul 
Island. St. Paul Village. LACM No. 7:1-21,. X. 200. 9, Radular tooth configuration (see Fig. H for legend). 10, Basal plate niorphology 
(see Fig. Hfor legend). 



Vol. 93 (2-3) 



April 23, 1979 



thp: nautilus as 



fn 




c 



V 




I 



2 





<^>^. 




B 





10 



For explanations, see opposite page (Lindberg on Acmaeidae). 



54 thp: nautilus 



April 23. 1979 



Vol. 93 (2-3) 



The Radula of Collisella ochracea 

Although shell color varies significantly in this 
species, radular characters appear consistent. 

Grant (1938: pit. 30, Fig. 2) figured the radular 
strap and basal plates of C. ochracea, but did not 
discuss or figure tooth configuration or mor- 
phologj'. She did mention the presence of elon- 
gated uncini. McLean (1966: 77) described the 
lateral teeth and basal plate morphologj', and 
gave length/width ratios for the ribbon seg- 
ments. 

The radular tooth configuration of C. ochncea 
(Fig. 5) is typical of members of the genus. The 
first lateral teeth are close together on the an- 
terior end of the segment and are rounded distal- 
ly. The second laterals are posterior to the first 
laterals and are sub-rectangular, with broad 
straight cutting edges. The third laterals are obli- 
que and are distal to the second laterals; they are 
wedge-shaped and smaller than the other laterals. 
The uncini are elongate and curve over the 
posterior comers of the ventral plates. The tips 
may be slightly broadened. 

The basal plate morphology of the radula (Fig. 
6) is also typical of members of the genus. The 
first lateral plates are sub-rectangular; the second 
lateral plates broad and posteriorly rounded; and 
the third lateral plates are separated from the sec- 
ond lateral plates by a strong partial suture. 
The third lateral plate is biformed, the inner sec- 
tion rounded distally and extends beyond the sec- 
ond lateral plate edge. The outer section is 
pointed distally and extends to the vicinity of the 
uncini. The ventral plates are clearly defined and 
bear both a strong anterior suture and pro- 
cess-the anterior process is difficult to see in 
radular mounts with closely spaced segments. 



Natural History Notes 

Specimens of C. ochracea of both sexes, some 
with shell lengths of less than 5 mm, have been 
found in a gravid state, and some of these from 
central California are known to have been col- 
lected in the months of February through 
August. 

The bathymetric range of C. ochracea extends 
from the low intertidal (= 0.0 feet) to a little 



over 40 m. No .submergence in the southern por- 
tion of the distribution of this species appears to 
occur, although Baja California specimens appear 
limited to areas of cold-water upwellings. 

C ochracea also occurs in the turbid water of 
San Francisco Bay, California (37°48'N) on the 
sides and bottoms of small rocks embedded in 
sand and gravel sediments and on fouled pilings 
in Monterey Harbor. The occurence of C. ochracea 
in such habitats is not surprising in view of 
Yonge's (1962) report that C. ochracea has a man- 
tle current pattern similar to that of Notoacmea 
test7idinali% a species often found associated with 
sediment-laden water. 

DISCUSSION 

While the epizoic and coralline forms of C. 
ochracea are directly referable to particular 
substrata, the solid and tessellate forms appear to 
occur homogeneously in the intertidal and sub- 
tidal areas of central California. However, in a 
survey of over 400 specimens some geographic 
correlations of these forms were noted. Tesselate 
forms predominate in the southern part of the 
geographic distribution (south of 38°N) and 
decrease to the north; the solid forms predomi- 
nate in the north and appear to decrease to the 
south (Table 1). 

Some movement of individuals between sub- 
strata may exist. These movements are suggested 
by changes in shell morphology and shell color. 
Solid forms have been examined with the fine 
reticulate pattern of the coralline form visible at 
the apex (Fig. 7). The presence of the fine 
reticulate pattern may indicate movement from a 
coralline substratum to the exposed rock reefs, 
the typical habitat of solid forms. Changes in 
shell morphology and color have also been noted 
for C. pelta which may change substrata 
(McLean, 1966: 59). 



Notoacmea testudinalis (Muller) 

Although well-known on the east coast of 
North America (Abbott, 1974; Emerson and 
Jacobson, 1976), Arctic Canada and Europe (Mac- 
pherson, 1971), the presence of Notoacmea 
testudinalis in the northeastern Pacific has been 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 55 



TABLE 1. Getiymphiciil Distribution of Solid and Teaselate Firrms o/Collisella ochracea iDdlj in the Ka-steni Piwijic. 



DEGREES NORTH LATITUDE 



SOLID FORM 
# of specimens % of specimens 



TLSSELLATE FORM TOTAL « OF 

# of specimens % of specimens SPECIMENS 



<32 


2 


2 


116 


98 


118 


32-35 


18 


IB 


80 


82 


98 


36-37 


54 


38 


88 


62 


142 


38-40 


22 


63 


13 


37 


35 


41-43 





— 


1 


100 


1 


44-46 





— 





— 





47-49 





— 





— 





>49 


12 


92 


1 


8 


13 


E 


108 




299 




407 



the subject of considerable debate. Dall (1871) 
considered N. testudinalis to be readily discern- 
able from Acmaea patina [= Notoacmea scutum] 
and to occupy a different habitat. In 1879, Dall 
reversed his position and r^arded the two as 
varieties of a single species. Grant (1938) also 
considered the two to be of subspecific rank and 
to intergrade in the Alaskan Arctic. McLean 
(1%6), Abbott (1974), and Emerson and Jacobson 
(1976) consider A^. testudinalis to be limited to 
Atlantic and Canadian Arctic waters with a cog- 
nate, A^. scutum, in the eastern Pacific. Moskalev 
(1964) considered A^. testudinalis to be present in 
Arctic waters and to extend down the east coast 
of Asia. 

After examining shells and radulae of speci- 
mens from Alaska and comparing these to Cana- 
dian Arctic, eastern Atlantic, and European spec- 
imens of N. testudinalis. I have concluded that N. 
testudinalis occurs in the northeast Pacific and 
that Ball's first account (1871) was correct as to 
the species habitat and distribution. Based on 
materials in the collections of the Los Angeles 
County Museum and the California Academy of 
Sciences, the west American distribution of this 
species in Alaska is from Point Barrow (7r22'N) 
(CASG #35056) to Goose Island, Icy Strait 
(58°13'N) (CASG #48915) and eastward to the 
Pnbilof Islands (.57°08'N, 170°15'W) (CASG 
#21975). In the eastern Pacific its habitat appears 
to be subtidal, although it occurs intertidally in 
the eastern Atlantic and Europe. Its subtidal 
habitat may contribute to its success in northern 
waters, as it occurs below the level of sea ice and 



low winter air temperatures. It has also been sug- 
gested that this species may migrate into the sub- 
tidal during the winter to avoid adverse condi- 
tions (Willcox, 1905: 327). In comparison, A^. 
scutum is an intertidal species, not knovm to 
migrate and its northern distribution may be 
limited by sea ice and adverse winter weather. 
Therefore, in those areas where these two species' 
geographical distributions overlap (the Aleutians 
to Icy Strait, Alaska), A^. scutum and A', testudi- 
nalis appear to be segregated by habitat. 

The occurence of A^. testudinalis in the eastern 
Pacific is similar to the distribution of Coliisella 
alveus (Conrad. 1831) which occurs in both the 
North Pacific and the North Atlantic. 

Arguments against the presence of both A'. 
scutum and A^. testudinalis as separate species in 
the eastern Pacific (Dall, 1879; Test, 1938) have 
been based on the presence of supposed in- 
tergrades (hybrids) in the Arctic. While the 
similarities of shell micro-structure and radular 
morphology suggest that speciation has been re- 
cent, I consider A^. testudinalis and N. scutum 
sufficiently dissimilar to be considered specific. 

Comparison of 
Notoacmea testudinalis and Coliisella ochracea 

Although the tessellate form of C. ochracea ap- 
pears to be uncommon in the higher latitudes, it 
can be confused with N. testudinalis (cf. Figs. 1 
and 8b). Both species have similar gross color pat- 
terns (Fig. 8), and in both, external sculpture con- 
sists of numerous, fine, non -bifurcating riblets. 



56 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



As in most forms of C. ochracea, the internal 
stain of N. testudinalis does not cover the apex, 
and the external apex of both is white. However, 
the shell of A^. testudinaiia is larger and heavier 
than that of C. ochracea, and the internal stain is 
sharp and distinct; in C. ochracea, the stain is 
typically obscure or lacking. 

As suggested by their generic allocations, C. 
ochracea and A^. testvAinalis differ in radular 
structure (Figs. 9-10). The radula of C. ochracea 
bears uncini; N. testudinalis lacks them. In N. 
testudinalui the first and second lateral teeth are 
elongate and pointed distally, rather than short 
and blunt as in C. ochracea. The basal plates of 
N. testudinalis differ from those of C. ochracea in 
that the third lateral plates are distinct and are 
located laterally from the second lateral plates. 
They are also lobate rather than bi formed as in 
C. ochracea. The ventral plates of both species 
bear anterior processes. 

ACKNOWLEDGMENTS 

I wish to acknowledge Eugene V. Coan, LACM 
and CASG; James H. McLean, LACM; and EJarry 
Roth, CASG, for their criticism of this paper. Dr. 
McLean also loaned numerous specimens. My 
special thanks to Maurice Giles, CAS, who 
photographed and reduced the figures. This work 
was supported, in part, by SEA GRANT R/CZ-28. 

LITERATURE CITED 

Abbott, R. T.. 1974. American Seashells. 2nd ed.: 1-663. Van 

Nostrand Reinhold, N. Y. 
Brewer, B. A., 197.5. Epizoic limpets on the black turban snail, 

Tegulafunebralis (A. Adams, 1855) The Veliger 17: .307-310. 
Burch, J. Q.. 1946. Minutes, Cmwh. Ouh of So. Calif. 57: 1-40. 
Carlton. J. T. and B. Roth. 1975 Phylum Mollusca: shelled 

gastropods. In: R. I. Smith and J. T. Carlton (eds.). Light's 

Manual: Intertidal Invertebrates of the Central California 

Coast: 467.514. Univ. Calif. 
Dall, W. H., 1871. Descriptions of sixty new forms of moliusks 

from the west coast of America and the north Pacific 

Ocean, with notes on others already described. AmFi: Jour. 

0.»W(. 7: 9.3-160. 



1879. Report on the limpets and chitons of 

Alaskan and Arctic regions, with descriptions of genera and 
species believed to be new. Pmc. U.S. Nat. Miis. 1: 281-.344. 

. 1914. Notes on some northwest coast Acmaeas. 



neNautihwsTS: 13-1.5. 

1921. Summary of the marine shellbearing 



moliusks of the northwest coast of America . . . Bull. i'S 

Nat. Mtis. 112: 1-217. 
Emerson, W. K. and M. K. Jacobson. 1976. The American 

Mtiseum of Natural History Guide to Shells . . .: i-xviii. 

1-482. Adfred A. Knopf 
Fritchman, H. K. II. 1961. A study of the reproductive cycle 

in the California Acmaeidae (Gastropoda). The Vetiger 3: 

57-63. 
Grant. A. R.. 1933. A revision of the California limpets of the 

genus Acniaea Ek;hscholtz. Masters of Arts Thesis. Dept. of 

Zool., Univ. Calif., Berkeley: 1-142. 
19.38. A systematic revision of the genus Aemaea 

Eschscholtz, including consideration of ecology and specia- 

tion. Ph. D. Thesis. Dept. Zool.. Univ. Calif. Berkeley: l-4;fi. 
Keen. A. M.. 1937. An abridged check list and bibliography of 

west North American marine Mollusca: 1-87. Stanford 

Univ. 
Light, S. F.. et. at.. 19,54. Intertidal Invertebrates of the Cot- 

tral California Coast: 1-446. Univ. Calif. 
Macpherson. E.. 1971. The Marine Molluscs of Arctic Canada. 

Nat. Mm. Nat. Sci.. Pubt. Oceanogr. 3: 1-149. 
McLean. .1. H.. 1966. West American prosobranch Gastropoda: 

superfamilies Patellacea. Pleurotomariacea and Fissurel- 

lacea. Ph. D. Thesis. Dept. Zool.. Stanford Univ.: 1-262. 
1969. Marine shells of southern California. Los 

Angeles County Mus. Nat. Hist. Sci. Ser. 24, Zool. 11: 1-104. 
Moskalev, L. I.. 1964. Distribution of Acmaeidae (Gastropoda, 

Prosobranchia) in the North Pacific. Doklady. Akademii 

Nauk. SSSR 158: 1221-1222. [in Russian] 
Oldroyd, I. A.. 1927. The Marine Shells of the West Coast of 

North America 2: 1-340. Stanford Univ. Pub., Univ. Ser., 

(jeol.Sci. 
Pilsbry. H. A.. 1891. Acmaeidae. Manual of Conch. 13: 1-18.5. 

Philadelphia. 
Smith, A. G. and M. Gordon, 1948. The marine moliusks and 

brachiopods of Monterey Bay. California and vicinity. Proc. 

Calif Acad. Sci. 26: 147-245. 
Test. A. R. (Grant). 1945. Ecolog>' of California Acniaea. 

Ecology 26: 395-405. 
1946. Speciation in limpets of the genus Acmaea. 

Univ. Michigan. Contrib. Lab. Vert. Biol. 31: 1-24. 
Willoox, M. A.. 1905. Biology of Acmaea testudinalis Muller. 

Amer. Nat. 39: 325-a33. 
Yonge, C. M.. 1962. Ciliary currents in the mantle cavity of 

species of /lanwa. The Veligeri: 119-123. 



NEWS 
Hans Bertsch h;us been appointed Curator of EJerkeley. He has published over 30 papers on 
the Department of Marine Invertebrates at the opisthobranchs, and has had extensive field ex- 
San Diego Natural History Museum (P. 0. Box perience in Panama, Baja California, Hawaii and 
1390. San Diego, CA 92112). Dr. Bertsch was bom California. Dr. Bertsch was previously Assistant 
in 1944 in St. I^ouis, Missouri, received his Ph. D. Professor in biology at the Chaminade University 
in 1976 from the University of California, of Honolulu. 



Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 57 



TROPICAL FAUNAL AFFINITIES OF OPISTHOBRANCHS 
FROM THE PANAMIC PROVINCE (EASTERN PACIFIC) 



Hans Bertsch 

Department of Marine Invertebrates 

Natural History Museum, Balboa Park 

P.O. Box 1390, San Diego, CA 92112 

ABSTRACT 
This is a preliminary analysis of the distribution patteitis of species of 
opisthobmnchs (Gastropoda) in the eastern Pacific that are kimum to occur 
elsewhere in the tropics. 



The opisthobranch fauna of the Panamic pro- 
vince (tropical West America) shares the greatest 
number of common species with the Califomian 
temperate province (Bertsch, 1973a). Since 1970. 
various zoogeographic analyses of opisthobranch 
faunas from other marine provinces have been 
published (e.g., Franz, 1970, 1975; Thompson, 
m&a.etai). 

Marcus (1977) enumerated the western Atlantic 
opisthobranchs, noting which species occur in 
other marine provinces. She lists species common 
to the Caribbean and tropical west American pro- 
vinces and some amphi-Atlantic tropical forms. 
This extremely useful tabulation should be used 
with some reservation because certain species 
listed as "circumtropical" have not yet been 
reported from the Pacific coast of America (and 
hence are not universally circumtropical), and 
sources of the distributional data are at times 
unclear. 

Emerson (1978) has compiled a list of the pro- 
sobranch gastropods and bivalves which are com- 
mon to the Indo-Pacific and the eastern Pacific. 
This preliminary note is to compliment his study, 
so that a direct comparison can be made between 
the opisthobranchs and the prosobranchs. It is 
also intended to encourage further exchange of 
information on Panamic opisthobranchs. Only 
several tentative generalizations are presented 
because there is still much to be learned about 
the Panamic opisthobranch fauna. 

Affinities 

Table 1 summarizes the distribution patterns 
of species of opisthobranchs in the eastern Pacific 



that are known to occur elsewhere in the tropics. 
North-south range distributions (i.e., affinities 
with the temperate Califomian and Peruvian 
provinces) are generally not included. Also omit- 
ted are the pelagic Thecosomata, a group with 
several circumtropical species. 

Emerson (1978) and most of the writers he 
cites, have divided the Panamic province into 2 
main portions: the offshore islands (Guadalupe, 
Revillagigedo, Clipperton, Cocos, and the 
Galapagos) and the continental shelf of west 
America (Gulf of California, Mexican and Central 
American coastline, and the Islas Tres Marias). 
The majority of Indo-Pacific prosobranch species 
occur in the eastern Pacific only on the offshore 
islands. By contrast, all of the opisthobranch 
species known from the eastern Pacific and any 
other tropical province occur on the mainland 
coast. Six species occur also at the Galapagos 

TABLE 1. Extra-provincial distributions of opisthobranch 
species ocairrijig in the eastern Pacific. Numbers are species 
with that distributional pattern. 





Cephala- 


Saoo- 


Ana- 


Nota- 


Nudi- 




spidea 


glossa 


spidea 


spidea 


branchia 


Indii- 












Pacific 








1 





3 


Circum - 












tropical 





KG) 


5(G) 


KG) 


■KP) 


Carib- 












bean 





KG) 





2(G) 


5(G) 


Miscel- 












laneous 





1 








.3 



G: One of the species (or the one species enumerated) oc- 
curs in the Galapagos Islands, in addition to being present 
on the mainland shelf of west America 
P: All four species are pelagic 



58 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



Islands. No inter-provincial tropical species is 
presently known to occur only on the offshore 
islands. Of course, published records of 
opisthobranchs from these offshore sites are e.x- 
ceedingly scarce. Nevertheless, the occurrence of 
ail these inter-provincial tropical species on the 
continental shelf is a very different pattern than 
that known for the prosobranchs. 

So far as is known, there are no strictly 
Panamic forms which also occur in the Indo- 
Pacific province. Excluding the circumtropicals, 
species in common between these two provinces 
are apparently Indo-Pacific in origin. 

The inter-provincial prosobranchs are primari- 
ly Indo-Pacific (48 species), with a very small 
number of circumtropical (tropicopolitan is 
Emerson's equivalent term) species (7). By con- 
trast, there are 11 circumtropical and 4 Indo- 
Pacific species of opisthobranchs in the Panamic 
province. 

Evolutionary relationships with species in 
other provinces (including generic-level affinities) 
have not been examined among the opistho- 
branchs. Although sister-species are well 
documented among prosobranch gastropods (Rad- 
win, 1969), they have not been reported for the 
opisthobranchs. Such studies would yield vital in- 
formation on the origins of the Panamic opis- 
thobranch fauna, and would make substantial 
contributions to our knowledge of opisthobranch 
phylogeny and speciation and to current concepts 
of evolutionary zoogeography. 

Ranges of the Individual Species 

Four species of nudibranch occur cir- 
cumtropically; they are all pelagic. These species 
are Phylliroe biicephala "Peron and Lesueur, 
1810," Cephalopyge trematoides (Chun, 1889), 
Fiona pinnata (Ek;hscholtz in Rathke, 1831), and 
Glaucus atlanticus Forster, 1777. 

Although some of the remaining species that 
comprise the data base for Table 1 may be able to 
swim periodically as adults, none are pelagic 
after metamorphosis from the veliger stage. In 
the following paragraphs, the distribution of each 
species in the Panamic province follows the loca- 
tions in other zoogeographical provinces from 
which it has been reported. 



Sacoglossa 

Lobiger souvertni Fischer, 18.56. Circumtropical 
(Baba, 1974). From tropical west America, south- 
ern Baja California (Isla San Jose and near Cabo 
San Lucas); Santa Cruz, Nayarit, mainland Mex- 
ico; Galapagos Islands (see Larson and Bertsch, 
1974). 

I'lil yhranchia viride (Deshayes, 1857). Carib- 
bean (Ev. Marcus and Hughes, 1974: 503-506). 
Gulf roast of Baja California; Nayarit, Me.xico; 
Galapagos Islands (Bertsch and Smith, 1973; Fer- 
reira and Bertsch, 1975). 

Stiliger fuscatus (Gould, 1870). The distribution 
of this species is classed as one of the "Miscel- 
laneous" types: north Atlantic coast of the 
United States; tip of South America; south- 
eastern coast of Australia (Thompson, 1973: 
240-243). Puerto Penasa), Mexiro, northern Gulf 
of California (Ferreira and Bertsch, 1975). This 
may be an introduced species (.sp«,sm Carlton, 
1975: 17). 

Anaspidea 

Dolnbella auricularia (Lightfoot, 1786). Indo- 
Pacific; Ecuador and Easter Island (Ev. Marcus 
and Er. Marcus, 1970: 191). Gulf roast of southern 
Baja California (Steinbeck and Ricketts, 1941: 
171, 539-541; MacFarland, 1966: 32-37). 

Aplysia dactylomela Rang, 1828. Cir- 
cumtropical (Ev. Marcus and Er. Marcus, 1967: 
38). Panama (Pilsbry, 1895: 88-89; Engel and 
Hummelinck, 1936: 6). 

Aplysia Juliana Quoy and Gaimard. 1832. Cir- 
cumtropical. Northern Gulf of California (Puerto 
Penasco, Sonora, Mexico) to Paita, Peru (Ev. Mar- 
cus and Er. Marcus, 1967: 155-159; Keen, 1971: 
808). 

Aplysia parvula Morch, 1863. Circumtropical 
(Thompson, 1977: 110-112). Gulf of California 
(Lance, 1971: 60-63). 

Dolabrifera dolabrifera (Rang, 1828). Circum- 
tropical (Kay, 1964: 184-185). Northern Gulf of 
California to Panama (Bertsch, 1970a; Ferreira 
and Bertsch, 1975: 325); Galapagos Islands (Sphon 
and Mulliner, 1972: 149). 

Stylocheilus longicauda (Quoy and Gaimard, 
1824). Circumtropical (Ev. Marcus and Er. Mar- 
cus, 1967: 159-160). Gulf of California (Fanner, 
1967; Bertsch. 1970b, and 1973b). 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 59 



Notaspidea 

Berthellina citrina (Ruppell and Leuckart, 1828). 
Circumtropical (Thompson. 1970: 190-192; 1976a: 
167-169). Southern California; throughout the 
Gulf of California; Galapagos Islands (Bertsch, 
1970b; Lee and Brophy. 1969; Sphon and 
Mulliner. 1972: 150). 

Berthellina quadridens (Morch, 1863). Carib- 
bean (Thompson, 1977: 105-106). Panama Bay, 
Pacific coast (Ev. Marcus and Er. Marcus, 1967: 
43-44). 

Pleura branchus areolatum (Morch, 1863). 
Caribbean (Er. Marcus and Ev. Marcus, 1970: 55), 
south-central Atlantic (Ascension Island; 
Rosewater, 1975: 25), and west Africa (Edmunds, 
1968: 85). Northern Gulf of California (Puerto 
Penasco, Sonora, Mexico) to Panama; Galapagos 
Islands (Bertsch and Smith, 1973: 169). 

Nudibranchia 

Berghia major (Eliot, 1903) (includes Baenlidin 
amnkusana Baba, 1937). Indo-Pacific (Edmunds, 
1969: 467); Oahu, Hawaii (pers. obser., August 
1977). Gulf of California (Farmer, 1966; Ferreira 
and Bertsch, 1975: 328-329). 

Doriopsis viridis Pease, 1861. Indo-Pacific 
(Young, 1967: 160-161). Southern Gulf of Califor- 
nia; known only from 1 specimen (Bertsch, 1971). 

SpuriUa alba (Risbec, 1928). Indo-Pacific (Ed- 
munds, 1969: 465-466). Coast of mainland Mexico, 
from near Guaymas, Sonora, to Punta Mita, 
Nayarit (Sphon, 1971, 1978). 

The four circumtropical nudibranchs are 
pelagic. They were treated in a previous section. 

Cadlina evelinae Marcus, 1958. Caribbean: 
Brazil and Jamaica (Thompson, 1977: pit. 2; Ev. 
Marcus, 1977: 9). Pacific coast of Baja California; 
Gulf of California (Ev. Marcus and Er. Marcus, 
1967: 168-170). 

Dendrodoris krebsii (Morch, 1863). Caribbean 
(Meyer, 1977: 304). Northern Gulf of California to 
Panama; Galapagos Islands (Bertsch, 1973b: 109; 
Meyer, 1977). 

Pkidiana lynceus Bergh, 1867. Caribbean (Ed- 
munds, 1964: 16-18). Pacific coast of Panama Ca- 
nal Zone (Ev. Marcus and Er. Marcus, 1967: 111- 
112). 

Spurilla neapolitana (Delle Chiaje, 1823). 
Caribbean and Mediterranean (Ev. Marcus and 



Er. Marcus, 1967: 118-119). Gulf of California 
(Alex Kerstitch, pers. comm.). 

Tayiiva ketos Marcus and Marcus, 1967. Carib- 
bean (different subspecies; Er. Marcus and Ev. 
Marcus, 1970: 65-66). Northern Gulf of California 
to Bahia de Banderas, Nayarit, Mexico (Ferreira 
and Bertsch, 1975: 327). 

The remaining 3 species of nudibranchs have 
"Miscellaneous" distributions (i.e., they are not 
Panamic-Indo-Pacific, Panamic-circumtropical, 
nor Panamic-Caribbean). 

Aeolidiella takanosimensis Baba, 1930. Japan 
(Baba, 1930); Mediterranean (Schmekel, 1968: 
122-123); Oahu, Hawaii (pers. obser.; 1 specimen, 
Wailupe, 19 May 1977; 7 specimens, Earthwatch 
team members, Hauula, 14 June 1978). Southern 
California (Sphon, 1971); Bahia San Marte, Baja 
California del Sur, Mexico (Ferreira and Bertsch, 
1975: 329). This is possibly an introduced species 
to Hawaii and the eastern Pacific. 

Coryphellina rubrolineata O'Donoghue, 1929. 
Suez Canal, Australia, Japan, Brazil. San 
Agustin, Sonora, Mexico (Ev. Marcus and Er. 
Marcus, 1970: 210-211). 

Limenandra nodosa Haefelfinger ^and Stamm, 
1958. Mediterranean; Caribbean. Bahia Las Cruces, 
Baja California del Sur, Mexico (Bertsch, 1972). 

ACKNOWLEDGMENTS 

I am grateful to The Center for Field Research 
for a grant that enabled me to collect specimens 
in Hawaii during June 1978. I thank especially 
the following members of the Hawaiian Mollusks 
1978 Earthwatch team who collected specimens 
reported in this paper: Brian McElaney, Steve 
Norton, Larry Targett, Gregg Wilson, and Dr. 
Mel Brophy. I also thank Alex Kerstitch for sup- 
plying data, and Dr. William K. Emerson for 
comments. 

LITERATURE CITED 

Baba, Kikutaro. 1930. Studies on Japanese nudibranchs (3). A. 

Phyllidiidae. B. Aeolididae. Venus 2(3): 117-125; pi. 4; 5 

text figs. (10 December 1930) 
. 1974. Some comments on Lobxger souverbii 

Fischer. 1856, re-identified, of Japan (Opisthobranchia: 

Sacoglossa: Lobigeridae). The Veliger 16(3): 253-257; 3 text 

figs. (1 January 1974) 
Bertsch. Hans. 1970a. Dolabrifera dolabrifera (Rang, 1828): 

Range extension to the eastern Pacific. The Veliger 13(1): 

110-111; 1 text fig. (IJuly 1970) 



60 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



. 1970b. Opisthobranchs from Isla San Francisco, 

Gulf of California, with the description of a new species. 
Gmtrib. Sri.. Santa Barbara Mm. Nat. Hist, t 1-16; 13 text 
figs. (1 December 1970) 

. 1971. Natural histun' and occurrence of 



opisthobranchs of Las Cruces, Baja California, Mexico, and 
vicinity. Abstr. Proc. Third Ann. Meet. West. Soc. Malac., 
The Echo 3: 16. (7 March 1971) 

_. 1972. Two additions to the opisthobranch fauna 



of the southern Gulf of California. The Veliger 15(2): 
103-106; 1 pi.; 3text figs. (1 October 1972) 
1973a. Zoogeography of opi.sthobranchs from 



tropical west America. Abstr. Proc. Fifth .Ann. Meet. West. 
Soc. Malac.. Vie Echo 5: 47-.54. (.5 March 1973) 

1973b. Distribution and natural history of 



opisthobranch gastropods from Las Cruces. Baja California 
del Sur. Mexico. The Veliger 16(1): 105-111; 2 maps. (1 .July 
1973) 
and Alberic A. Smith. 1973. Observations on three 



opisthobranchs (MoUusca: Gastropoda) of the La Paz area. 
Baja California, Mexico. Southwestern Naturalist 18(2): 
165-176; 1 text fig. (29 June 197,3) 

Carlton. James T. 197.5. Introduced intertidal invertebrates. 
In: R. I. Smith and J. T. Carlton (ed.). Light's Manual: In- 
tertidal Invertebrates of the Central California Coast. 
University of California Press, pp. 17-25 (8 May 197.5) 

Eximunds. Malcolm. 1964. Eolid moUusca from Jamaica, with 
descriptions of two new genera and three new species. Bull 
Mar Sri. Gulf Carib. 14(1): 1-.32; 16 te.xt figs. (19 March 1964) 

1968. Opisthobranchiate mollusca from Ghana. 

Proc. Malac. Soc. London 38(1): 83-100; 12 text figs. (April 
1968) 

1969. Opisthobranchiate mollusca from Tanzania. 



I. Eolidacea (Eubranchidae and Aeolidiidae). Proc. Malac. 

Soc. Lond. 38(.5): 451-469; 10 text figs. (August 1969) 
Einerson. William K. 1978. Mollusks with Indo-Pacific faunal 

affinities in the Eastern Pacific Ocean. The Nautilus 92(2): 

91-96. (27 April 1978) 
Engel, Hendrick, and P. Wagenaar Hummelinck. 19.36. Ueber 

westindische Aplysiidae und Verwandten anderer Gebiete. 

Capita Zoologica 8(1): 1-76; 43 text figs. 
Farmer, Wesley M. 1966. Range extension of Berghia 

amakusana (Baba) to the east Pacific. The Veliger 9(2): 251; 

1 text fig. (1 October 1966) 
. 1967. Notes on the opisthobranchia of Baja 

California. Mexico, with range extensions. —II. The Veliger 

9(3): ^0-:}42; 1 text fig. (1 .January 1967) 
Ferreira, Antonio J., and Hans Bertsch. 197.5 Anatomical and 

distributional observations of some opisthobranchs from the 

Panamic faunal province. The Veliger 17(4): 323-330; 3 pis.; 

1 text fig. (1 April 1975) 
Franz, David R. 1970. Zoogeography of northwest Atlantic 

opisthobranch molluscs. Mar. Biol. 7(2): 171-180; 5 text figs. 

(October 1970) 
. . 197.5. An ecological interpretation of nudibranch 

distribution in the northwast Atlantic. The Veliger 18(1): 

79-83; 3 te.xt figs. ( I .luly 1975) 
Kay. E. Alison. 1964. The Aplysiidae of the Hawaiian Islands. 

Proc. Malac. Soc. Lond. 36(3): 173-190; pi. 8: 1 text fig. 

(December 1964) 



Keen, A. Myra. 1971. Sea Shells of Tropical West America: 
marine mollusks fi-om Baja California to Peru. Stanford 
Univ. Press, Stanford, Calif xiv -I- 1066 pp.; ca. 4000 figs.; 
22(.«lor pis. (1 September 1971) 

I.ance. .James R. 1971. Observations on the sea hare Aplysia 
parvula (Gastropoda; Opisthobranchia) from the Gulf of 
California. The Veliger 14(1): 60-63; 4 text figs. (1 July 
1971) 

Larson, Mary, and Hans Bertsch. 1974. Northward range ex- 
tensions for Lobiger smiverhii (Opisthobranchia: Sacoglossa) 
in the eastern Pacific. The Veliger 17(2): 22.5. (1 October 
1974) 

Lee, Richard S., and Patrick Brophy. 1969. Additional 
bathymetric and locality data for some opisthobranchs and 
an octopus from Santa Barbara County, California. The 
Veliger 12(2): 220-221. (1 October 1969) 

MacFarland. Frank Mace. 1966. Studies of opisthobranchiate 
mollusks of the Pacific coast of North America. Mem. Calif 
Acad. Sci. 6: xvi -I- 546 pp.; 72 pis. (8 April 1966) 

Marcus, P'rnst, and Eveline du Bois-Re.vmond Marcus. 1970. 
Opisthobranchs from Curasao and faunistically related 
regions. Stud. Fauna Curacao Carib. Isl. 33(122): 1-129; 160 
text figs. 

Marcus, Eveline du Bois-Re>'mond. 1977. An annotated 
checklist of the western Atlantic warm water opistho- 
branchs. Jm^r. Moll. Studies Suppl. 4: 1-22 (November 1977) 

, and Helen P. I. Hughes. 1974 Opisthobranch 

mollusks from Barbados. Bull. Mar. Sri. 24(3): 498-532; 56 
text figs. (27 November 1974) 

, and Ernst Marcus. 1967. American opisthobranch 



mollusks. Studies in Tropical Oceanography (U'niv. Miami 

Inst. Mar. Sci., Miami. Florida), no. 6: viii -t- 256 pp.; figs. 

1-155 -I- 1-95. (22 December 1967) 
1970. Some gastropods from Madagascar and west 

Mexico. Malacologui 10(1): 181-223; 93 text figs. (14 

November 1970) 
Meyer. Kaniaulono B. 1977. Dorid nudibranchs of the Carib- 
bean ojast of the Panama Canal 7/me. Bull. Mar. Sri. 27(2): 

299-.307; 4 te.xt figs. (27 April 1977) 
Pilsbry. Henry A. 1895-1896. Manual of Concholoyy. \'ol. 16: 

262 pp.; 74 pis. 
Radwin, George E. 1969. A recent molluscan fauna from the 

Caribbean coast of southeastern Panama. Ti'ans. San Diego 

Soc. Nat. Hist. 15(14): 229-236; 1 te.xt fig. (27 June 1969) 
Rosewater. .Joseph. 197.5. An annotated list of the marine 

mollusks of Ascension Island. South Atlantic Ocean. 

Smithsonian C(mtrib. Zool. 189: iv -I- 41 pp.; 24 te.xt figs. 

(130 May 1975) 
Schmekel, Luise-Renate. 1968. Ascoglossa, Notaspidea und 

Nudibranchia im litoral des Golfes von Neapel. Rev. Suisse 

Zool. 75(1): ia3-155; 21 text figs. (March 1968) 
Sphon. Gale G. U)71. New opisthobranch records for the 

eastern Pacific. Tlir Vrluirr 13(4): :i58-:«t. (1 April 1971) 
. 1978. Additional notes on Spurilla alba (Risbec, 

1928) (Mollusca: Opisthobranchia). The Veliger 21(2): 305. (1 

October 1978) 
and David K. Mulliner. 1972. A preliminary list 



of known opisthobranchs from the Galapagos Islands col- 
lected by the Ameripagos Expedition. The Veliger 15(2): 
147-1.52; 1 map (I October 1972) 



Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 61 



Steinbeok. John, and Edward F. Ricketts. 1941. Sea ofCoriez. 

Tne \'ikinR Press. New York, x + .598 pp.; 40 pis. 

(DeceniljerlWl). 
Thompson. Thomas E. 1970. I>;ast^rn Australian Pleurobranch- 

omorpha (Gastropoda. Opisthobranchia). Jour. Zaal.. London 

160(2): 173-198; 1 pi.; 11 text figs. (16 February 1970) 
1973. Sacoglossan gastropod molluscs from 

eastern Australia. Proc. Malac. Soc. Lond. 40(4): 239-2.51; 3 

te.xt figs. (April 1973) 
. 1976a. Biologj- of opisthobranch molluscs. Vol. 1. 



1976b. Introduction: Zoogeography of nudi- 

branchs. Jour. Moll Shulies. 42(2): 295-:3()2 (pagination in- 
cludes several papers by various authors). (.August 1976) 

1977. Jamaican opisthobranch molluscs I. Jnur. 



The Ray Society, London. 207 pp.; 21 pis.; 106 text figs. 



Moll. Studies 43(2): 93-140; 3 pis.; 32 text figs. (July 1977) 

Young, David K. 1967. New records of nudibranchia 
(Gastropoda: Opisthobranchia: Nudibranchia) from the cen- 
tral and west-central Pacific with a description of a new 
species. The Veliyer 10(2): 1.59-173; 18 text figs. (1 October 
1967) 



A NOTE ON THE DISTRIBUTION AND FOOD PREFERENCE OF 
CADLINA LAEVIS (NUDIBRANCHIA: CHROMODORIDAE)' 

Melissa A. Barbour 

1839 9th Street 
Alameda. CA 94501 



ABSTRACT 
The distribution and food preference of the nudibranch, Cadlina laevis (Linnaeus. 
1767) are discussed. This species has an amphiatlantic distribution from Cape Cod 
on the American coast to the Mediterranean on the European coast. It appears to 
feed on the soft, dendroceratid sponge, Halisarca dujardini Johnston. 



The dorid nudibranch Cadlina laevis (Linnaeus, 
1767) has an amphiatlantic distribution. Lemche 
(1938) reported the distribution of C. laevis ". . . 
from the Gulf of Mexico, Greenland, several 
localities in the Arctic Sea, the Faroes, the 
Shetlands, the whole coast of Norway, south- 
wards along the west coasts of Europe, and from 
the Mediterranean." The inclusion of the Gulf of 
Mexico in this list is probably an error since 
Franz (1970) reported the southern limit of this 
boreo-subarctic species to be Cape Cod, Massa- 
chusetts. There are no reports of C. laevis from 
the Gulf of Mexico in the recent literature. It is 
probable that Lemche meant the "Gulf of Maine" 
where this species does occur. While a student at 
Northeastern University, Boston, Massachusetts, I 
made field observations on this species at East- 
port, Maine, in August and September of 1969 
and 1970, and carried out laboratory studies at 

'. Osntribution no. 69. Marine Science Institute, Northeastern 
University. Nahant, Massachusetts. 



the Marine Science Institute at Nahant, Massa- 
chusetts. 

FIELD OBSERVATIONS 

C. laevis is found in the lower intertidal to 
subtidal regions of exposed rocky coastal areas. It 
was observed by me under rocks at approximate- 
ly -3.0 feet below mean low water (MLW). The 
habitat consisted of boulders resting on bedrock 
around and imder which small amounts of sandy 
mud were trapped. Some algal growth was pre- 
sent on the boulders. Other invertebrates, in- 
cluding brachiopods, colonial and solitary 
tunicates, and sponges, were also attached to the 
underside of these boulders. TTie unspiculated 
dendroceratid sponge, Halisarca dujardini; 
Johnston, was commonly found encrusting the 
undersides of these boulders. C. laevis was 
observed in close proximity to this sponge, being 
either within a small cleared area at the center 



62 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



of a Halimrca mat or at the edge of it. The 
anterior mantle of the nudibranch typically cov- 
ered the edge of the sponge mat. When the nudi- 
branch was removed a concavity in the edge of 
the sponge was seen. This concavity conformed to 
the size and shape of the anterior portion of the 
dorid. The nudibranch was only rarely found on 
rocks without the sponge. 

LABORATORY OBSERVATIONS 

Specimens of C. laevis were kept in laboratory 
aquaria for up to 10 months without any obvious 
food source. During this time the animals were 
observed to release fecal strands and to spawn. 
Animals dissected during this period had a brown 
material in the stomach. I believe this material 
was alagal slime from the sides of the aquaria on 
which the nudibranchs were able t*j maintain 
themselves. Eggs were deposited in early spring. 
The young hatched after approximately 2 months, 
but did not mature. When //a/ isarra -encrusted 
rocks were placed in the aquaria the nudibranchs 
were observed to feed on the sponge (M. P. Morse, 
pens, cornm.). 



DISCUSSION 

Two of Swennen's (1961) three criteria for 
determining preferred food of nudibranchs were 
met in this study: (1) the animal was found in 
the field in close conjunction with the probable 
food; and (2) the animal fed on the probable food 
in the laboratory. The third criterion, the main- 
tenance of the animal on the preferred food in 
the laboratory, was not met in this study. 

There are, in addition to the above field and 
laboratory observations, morphological and 



anatomical indications that C. Inei-U feeds on soft 
sponges. The body is oval, with a broad foot and 
wide radula; the mouth lacks true mandibles. The 
digestive tract lacks a buccal pump, has a 
reduced caecum, and there is a reduction in the 
number of gland cells throughout the tract (Bar- 
bour, 1;)71). These modifications have been pre- 
viously described for feeders of soft sponges by 
Forrest (1953) and by Thompson (1962). 

ACKNOWLEDGMENTS 

I wish to thank Dr. M. P. Morse and Dr. N. W. 
Riser for their help and support during the 
preparation of this manuscript and Dr. Welton L. 
Lee, David R. Lindberg and James E. Sutton for 
their reviews and comments on it. Part of this 
study was submitted in partial fulfillment of the 
requirements for a MS degree at Northeastern 
University. 

LITERATURE CITED 

Barbour. M. A. 1971. The functional morphology of the 
digestive tract of the dorid nudibranch. Cadlina laevis 
Bergh, 1879 [sic]. Unpublished MS thesis. Northeastern 
University, Boston, Massachusetts. 64 pp. 

Forrest, J. E. 1953. On the feeding habits and morphology and 
mode of function of the alimentary canal in some littoral 
dorid Nudibranchiata Mollusca. Proc. Linn. Snr. London 
164(2): 225-2a5. 

Franz, D. R. 1970. Zoogeography of Northwest Atlantic 
opisthobranch molluscs. Afar. Biol. 7: 171-180. 

Lemche, H. 1938. Gastropoda opisthobranchiata. 77i€ Zoology 
of Iceland 4(51): 1-54. 

Swennen, C. 1961. Data on distribution, reproduction and 
ecolog>' of the nudibranch molluscs occurring in the 
Netherlands. A'eMer/(i«(is ,/. Sea Rejteuirh 1: 191-240. 

Thomiwon, T. E. 1962. Grazing and the life c.vcle of British 
nudibranchs. In: Grazing in Terr&strial and Marine En- 
vironments, Ed. D. J. Crisp. Sijmp. British Ecol. Soc., 4: 
275-297. 



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Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 63 



CATINELLA PARALLELA. A NEW SUCCINEIDAE (PULMONATA) FROM 

MIDWESTERN UNITED STATES 

Dorothea S. Franzen 

Illinois Wesleyan University 
Bloomington, Illinois 61701 

ABSTRACT 
Catinella parallela, a new sppcies of Siwcineidae. mid its reproductive oryans. 
chninioiiomeii. shell and detailed habitats are described. The knoum geographic 
range extends from western Elinois to western Indiana, between 38°10' - J^O'SO'N 
latitude. This species was taken from three types of habitats. 



In the coui-se of my field studies on succineid 
gastropods in the midwestem states I have found 
a large, hitherto undescribed species. 

Catinella parallela n. sp. 

Description of Holotype: Shell: amber-colored, 



translucent, imperforate, elongate-ovate, com- 
posed of three and one-third inflated whorls 
separated by a deeply incised suture; height 10 
mm, width 6.1 mm. A knoblike nuclear whorl 
tops the acute spire; whorls increase rapidly in 
size resulting in a tumid ultimate whorl; nuclear 






B 






FIG. 1. A, B, Hntotype of Catinella parallela, n. sp. (Height. 
10 mm). C. Paratype of Catinella parallela n. sp.. one-half 
mile X. White River. Knox County. Indiana (Height 11.7 
mm). D. Paratype of Catinella parallela n. sp.. Pere Mar- 



quette State Park, Jersey County. Illinois (Height 12.0 mm). 
E. F. Paratyi>e of Catinella parallela n. sjh. AVw Hardin, 
Greene County. lUinoi.': (Height 1-1.2 mm.) 



64 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



whorl finely granular; irregularly-spaced longi- 
tudinal striations, fine on the lower half of the 
nuclear whorl, increasing gradually, becoming 
coarser towards the aperture; ovate aperture oc- 
cupies nearly seven-tenths of height of shell 
(Table 1). Sharply-edged peristome very fragile; 
very thin callus discernible on ultimate whorl 
above the aperture; amber-colored columella 
follows inner border of peristome and curves as it 
disappears into the ultimate whorl (Fig. 1, A). 

Body and Mantle Surfaces: Surface of head 
and body wall cream-colored, coarsely and ir- 
regularly tuberculate; pigmentation of dorsal 
body surface consists of bands of dark flecks ex- 
tending from anterior end of head to junction of 
mantle and the body wall; mid-dorsally on head 
pigmentation forms a triangle, narrowing to a 
band between the superior (posterior) tentacles, 
dividing and continuing as a double band mid- 
dorsally the length of the body; the median 
triangle flanked on either side by a dark band, 
bending medially around the superior tentacles, 
paralleling the dorsal pair the length of the body; 
median triangle flanked on either side by a dark 
band which bends medially around the superior 
tentacle to parallel the mid-dorsal pair the length 
of the body; surface of both pairs of tentacles 
flecked; pigmentation of lateral body wall form- 
ing a broad horizontal band. 

The genital aperture, about 0.5 mm in length, 
surrounded by a white lip, situated on anterior 
right-hand side of body. On either side a pedal 
groove, continuous from labial palp to posterior 
tip of body, separates foot from lateral body wall; 
pedal groove paralleled by a less pronounced 
suprapedal groove. Shallow, vertical grooves in- 
cise the suprapedal and pedal grooves, margin of 
foot and the broad pigmented band. These ver- 
tical grooves produce shallow scallops along the 
margin of the foot especially when the animal is 
in a somewhat contracted state. The sole of the 
foot is cream -colored and unpigmented. 

The mantle collar is flecked overall. From 
anterior margin of mantle narrow bands of pig- 
ment, distinct near edge of collar, merge forming 
streaks over mantle surface. The kidney is out- 
lined by a dark band. 

Holotype: Catalogue no. FMNH 201444; 
Paratypes nos.: FMNH 201445, FMNH 201446, 



Molluscan Collection, Field Museum of Natural 
Histor>', Chicago, Illinois. Additional paratypes 
are in the private collection of the author. 

T)fncripti(in of Paratifpes: Shell: (Fig. 1, C-F) 
Shells of mature snails, attaining a height of 15.2 
mm, are comprised of 3 1/4 to 3 3/4 inflated 
whorls. Dimensions of the three largest shells, 
number of shells measured, and the median of 
each of the nine series measured, are recorded in 
Table 1. The range of the greatest height of the 
series of shells included in this study is from 10.2 
to 15.2 mm, and the range of the greatest width 
is from ■6.0 to 8.28 mm. The largest apertures of 
the shells of the nine series occupy from 65.8 to 
72.0 percent of the entire height of the shell. 
Other dimensions and relative dimensions are to 
be noted in Table 1. T^e largest shells were taken 
from the flood plain of the Illinois River, New 
Hardin, Green County, Illinois (Field #269) on 
June 22, 1966. To date I have not found mature 
snails sundving beyond the month of July. 

Reproductive Organs: (Fig. 2) The albumin 
gland (A, C - AG) triangular in form, composed 

of fine acini, is enclosed within a thin, tran.'^- 
parent sheath. The elongate, sube(iually biiobed 
seminal vesicle (A, C - SV) is enclosed with- 
in a thin, transparent, pigmented sheath. The 
darkly pigmented hermaphroditic duct (A, C - 
HD) and the bilobed seminal vesicle join to form 
the fertilization sac (A, C - FS) from which 
diverge the oviduct (OD) and the sperm duct (SD) 
which leads into the prostate gland (PG). The 
oval prostate gland, enclosed by a thin, 
transparent, pigmented sheath, is composed of 
acini which are coarser than those of the albumin 
gland. The length of the prostate gland exceeds 
that of the albumin gland (A, C). As the vas 
deferens approaches the penis from the prostate 
gland it follows the penis along its dorsal surface. 
As it enters the distal end of the penis it enlarges 
to form the epiphallus (B, C - EP) which enters 
the unsheathed penis (P) terminally. The penis 
enlarges immediately into a cylindrical form. The 
penial appendage (B, C - PA) whose base is 
almost one-half the length of the penis, originates 
subterminally where the penis joins the genital 
atrium (B, C - GA). The appendage expands 
horizontally to equal about two-thirds of the 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 65 



TABLE 1. Dimensioris of shells o/Catinella paiallela, ii. »p. The measiirements are of the three largest shells of each of the 9 series 
(6 liicntities) as indicated, hi the J,lh column of iieasnrentents are listed the mtios of the uidth of the shell over its height. In the 
last S columns air listed the ratios of the height of the aperture over the height of the shell, iridth of aperture over width of shell 
width ofapeiture oiwr height of aperture. 





No. 


of 






Width/ 


Height of 


Width of 


H. Ap./ 


W. Ap./ 


W. Ap./ 




Whorls 


Height 


Width 


Height 


Aperture 


Aperture 


H. Shell 


W. Shell 


H. Ap. 


Holotype 


3 


1/3 


10. mm 


6. 1 mm 


.61 


6.7 nun 


4.1 mm 


.67 


.67 




.61 


Type Locality 


3 


1/3 


10.2 


6.4 


.62 


7.4 


4,5 


.72 


.70 




.61 


Field «4S8 


3 


1/3 


9.5 


5.6 


.59 


6.4 


3.8 


.67 


.68 




.59 


Floodplain. Wabash R. 


, 






















White Co. , Illinois 
























June 20, 1977 
























Range (6 shells) 


3 
3 


1/3 


7.5 - 
10.2 


4.7-6.4 


.56-. 62 


5.1-7.4 


3.2-4.5 


.66-. 72 


.67-. 


73 


.59-. 62 


Median 






9.5 


5.6 


.59 


6.4 


3.8 


.67 


.68 




.59 


Field •458 


3 


1/2 


11.91 


6.7 


.563 


7.89 


5.51 


.662 


.822 




.698 


Floodplain, Wabash R. 


, 3 


1/2 


11.25 


6.33 


.563 


7.27 


5.00 


.646 


.790 




.688 


Wiite Co. , I llinois 


3 


1/3 


11.15 


7.00 


.628 


7.50 


5.38 


.623 


.769 




.717 


June 5, 1976 
























Range {12 shells) 


3 
3 


1/2 


6.3 - 
11.91 


3.61-7.0 


.53-. 628 


3.94-7.89 


2.78-5.51 


.623-. 711 


. .672- 


.869 


.606-. 717 


Median 






10.26 


6.24 


.573 


6.86 


4.42 


.670 


.798 




.684 


Field »461 


3 


1/2 


14.29 


7.44 


.521 


8.95 


5.76 


.626 


.774 




.644 


One-half mi. S of 


3 


1/2 


13.27 


8.80 


.663 


8.50 


5.74 


.640 


.652 




.675 


White River, Knox Co. 


, 3 


1/2 


13.04 


7.85 


.602 


•^.85 


5.20 


.602 


.662 




.662 


Indiana 
























June 6, 1976 
























Range (8 shells) 


3 

3 


1/3- 

1/: 


9.82- 
14.29 


6.28-8.80 


.521-. 663 


6.53-8.95 


4.48-5.76 


.585-. 678 


.652- 


.80 


.662-. 735 


Median 






12.70 


7.20 


.640 


7.56 


5.44 


.637 


.713 




.684 


Field »461 


3 


1/2 


10.6 


6.0 


.56 


6.7 


4.4 


.63 


.73 




.65 


One-half mi. .N of 


3 


1/3 


10.5 


6.10 


.58 


6.8 


4.5 


.64 


.73 




.66 


White River, Knox Co. 


, 3 


1/3 


9.8 


5.7 


.58 


6.0 


3.5 


.61 


.61 




.58 


Indiana 
























June 21, 1977 
























Range (28 shells) 


3 
3 


1/4- 
1/2 


8.2-10.6 


4.8-6.1 


.49-. 64 


5.1-6.8 


3.4-4.5 


.56-. 70 


.60-. 


77 


.56-. 66 


Median 






9.5 


5.6 


.59 


6.1 


3.7 


.64 


.67 




.61 


Field "462 


3 


1/2 


12.84 mm 


7.25 mm 


.565 


7.83 mm 


5.26 mm 


.610 


.726 




.672 


10 mi. N Vincennes, 


3 


1/2 


10.00 


6.09 


.609 


6.28 


4.17 


.628 


.685 




.664 


Knox Co. , Indiana 


3 


1/3 


9.47 


5.65 


.597 


S.78 


3.95 


.610 


.699 




.683 


June 6, 1976 
























Range (20 shells) 


3 
3 


1/3- 
1/2 


3.89- 
12.84 


2.50-7.25 


.474-. 643 


2.56-7.83 


2.0-5.26 


.528-. 658 


.641- 


.767 


.576-. 843 


Median 






8.03 


4.7S 


.597 


4.81 


3.27 


.577 


.688 




.684 


Field »187 


3 


1/2 


12.4 


7.5 


.60 


8.6 


5.4 


.69 


.72 




.62 


Pere Marquette State 


3 


1/3 


12.2 


7.0 


.57 


7.8 


4.6 


.64 


.65 




.59 


Park, Jersey Co. . 


3 


1/2 


11.7 


6.7 


.57 


7.5 


4.3 


.64 


.64 




.57 


Illinois 
























June IS, 1954 
























Range (7 shells) 


2 
3 


3/4- 
1/2 


8.9- 

12.4 


5.1-7.5 


.56-. 61 


6.2-8.6 


3.7-5.4 


.60-. 69 


.64-. 


72 


.57-. 66 


Median 






11.6 


6.7 


.57 


7.S 


4.6 


.65 


.70 




.60 


Field •269 


3 


3/4 


13.23 


8.20 


.620 


8.65 


5.61 


.654 


.684 




.649 


New Hardin, 


3 


1/2 


13.05 


7.80 


.598 


8.60 


5.68 


.659 


.728 




.660 


Greene Co., Illinois 


4 




13.00 


7.74 


.595 


8.30 


5.00 


.638 


.646 




.602 


July 11, 1964 
























Range (25 shells) 


3 
4 


1/3- 


10.10- 
13.23 


5.60-8.20 


.518-.645 


6.22-8.65 


4.36-S.68 


.606-. 711 


.631- 


.841 


.602-. 723 


Median 






11.60 


6.95 


.60 


7.59 


4.91 


.653 


.701 




.652 


Field 1269 


3 


1/2 


15.20 


8.28 


.545 


9.60 


6.40 


.632 


.773 




.667 


New Hardin, 


3 


1/2 


13.15 


7.35 


.559 


8.55 


S.95 


.650 


.810 




.696 


Greene Co. , Illinois 


3 


1/2 


12.82 


7.40 


.577 


8.20 


5.17 


.640 


.699 




.630 


June 22, 1966 
























Range (9 shells) 


3 


1/3- 


10. so- 




















3 


1/2 


ls. 30 


6.05-8.28 


.527-. 630 


6.95-9.60 


5.05-6.80 


.618-. 689 


.699- 


.863 


.630-. 777 


Median 






12.70 


7.22 


.576 


8.20 


5.36 


.640 


.810 




.696 


Field 11445 


3 


1/3 


12.15 


6. 85 


.564 


7. SO 


4.47 


.617 


.653 




.596 


0.8 mi. S Nutwood, 


3 


1/3 


11.51 


6.6 


.573 


8.0 


4.92 


.695 


.745 




.615 


Jersey Co. , Illinois 


3 


1/3 


11.45 


7.0 


.611 


7.50 


4. 52 


.657 


.646 




.603 


June 1, 1975 
























Range (14 shells) 


3 
3 


1/3- 
1/2 


8.42- 
12.15 


S. 08-7. 00 


.S66-.641 


5.20-8.0 


3.5S-4.92 


.610-. 708 


.646- 


.80 


. 596- . 72 


Median 






10.5 


6.12 


.603 


6.95 


4.45 


.657 


.742 




.648 



66 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 




FIG. 2. Reproductive organs o/Catinella parallela n. sp. AG. 
albumin gland: EP, epiphalhis: FS, fertilization sac: GA. 
genital atrium: HD, hermaphroditic duct: OD, oviduct: P. 
penis: PA, penial appendage: PG, prostate gland: PRM, penial 
retractor muscle: SD, sperm duct: SP, spermaiheca: SPD, 
spermathecal duct; SV, semina/ vesicle; VA, vagina; VD, ytw 
de/er«7is. 

length of the penis — the expanded portion paral- 
lels the penis (A, C). The vertical dimension of 
the appendage is almost twice that of the body of 
the penis. The internal walls of the penis and of 
the appendage are folded forming very prominent 
ridges projecting into the lumen. The internal 
foldings of the appendage can be noticed exter- 
nally by markings as indicated (B, C). Fibers of 
the broad, stout penial retractor muscle insert 
mainly onto the base of the penial appendage; 
lesser fibers insert onto the penis and onto the 
epiphallus(B,C-PRM). 

The globular spermatheca (Fig. 2, C - SP) is 
connected to the vagina by a stout spermathecal 
duct (SPD) which enlarges as it approaches and 
enters the vagina. The short vagina expands as it 
opens into the genital atrium (B - GA). 

The Radula: Radulae of seven paratypes of 
three localities were stained and mounted. The 
number of rows of teeth occurring on the radulae 
examined range from 84-90 (Table 2). There are 
few teeth to a row on the anterior-most rows; the 
number increases rapidly posteriorly. 



The number of marginals and laterals of rep- 
resentative rows of the seven radulae are re- 
corded in Table 2. Although there is an indi- 
vidual variation of the radulae and also of the 
rows of teeth of a radula, the ratio of marginals 
to laterals is approximately 1:1 Such a ratio is 
characteristic of the genus as noted by Quick to 
be true of Catinella (Sticcinea) arenaria ("B.-Ch.") 
(Quick. 19.33, Fig. 4, p. 296). 

The structural details of the individual teeth 
resemble those of the genus as described for 
European species by Quick (ibid). The charac- 
teristics of the teeth are described below and il- 
lustrated in Fig. 3, A. The central tooth (C) bears 
a broad basal plate having a posterior, serrated 
margin flanked on either side by a rounded boss. 
Ihe pointed mesocone extends downward to a- 
bout the lower third of the basal plate. A short, 
I)ointed ectocone flanks the mesocone on either 
side. 

The laterals (L-L) have a large, pointed meso- 
cone which, like that of the central tooth, extends 
downward to about the lower third of the basal 
plate. A small, pointed endocone is present. The 
singly pointed ectocone is sometimes divided into 
two cusps; this is especially true of the more 
lateral teeth. 

The marginals (L-M) smaller than the laterals, 
have a basal plate which is broader than long; 
this is especially true of the outermost marginals 
(Fig. 3). The small endocone is pointed; the 
pointed mesocone extends to the base of the basal 



T.\BLE 2. Fonnulae of representative rows of teeth of Cati- 
nella parallela new species. 









No. of 


Rows 




















Statloo 




Slide 


of le 


eth 


Row 


H 




I. 






L 




H 


Field Ho. 


1.1.5 


A 


S6 




1.7 


15 


- 


10 


- 


1 - 


IJ 


. 


15 


Jersey County, 
Illinois 








50 


1) 


- 


12 


- 


I - 


13 


- 


15 












5J 


11. 


- 


11 


- 


I - 


12 


- 


15 












65 


15 


- 


10 


- 


I - 


n 


• 


15 


Field Ko. 


269 


A 


90 




il 


10 


_ 


15 


_ 


_ 


16 


_ 


7 


Seat Hardin, 
Illlnoia 








J6 


11 


- 


15 


- 


- 


11. 


- 


9 






B 


88 




2i 


11. 


- 


10 


- 


- 


11 


- 


10 












1.6 


15 


- 


9 


- 


- 


10 


- 


12 






C 


88 




1.7 


15 


- 


10 


- 


- 


11 


- 


12 









92 




^9 


10 


- 




- 


- 


12 


- 


12 












5! 


15 


- 




- 


- 


11. 


- 


11 


Field No. 


<.61 


A 


81. 




1.5 


11 


_ 




- 




15 


_ 


11 


Knox Coun 
Indiana 


tj. 








55 


11 


- 




- ! 




10 


- 


12 












61. 


15 


- 




- 1 




15 


- 


15 






B 


88 




}!• 


11. 


- 




- 1 




11. 


- 


11. 












66 


11. 


- 




- 1 




12 


- 


16 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 67 



plate. The ectocone of the inner-most marginals is 
divided into two, while the outermost is divided 
into three cusps. 

The basal plates of the marginals are short and 
broad which is a distinctive feature of the genus 
Catinella as observed by Quick (1933, Fig. 4). The 
basal plates of the marginals of the radula in the 
genus Oxyloma are long and tapering as reported 
of Oxyloma (Succinea) pfeifferi ("Rossm.") by 
Quick (ibid, Fig. 1). This feature of the radula 
was observed in other species of Oxyloma by 
Franzen (1963, Fig. 1; 1966, pp. 64-65; 1969, Fig. 
1; 1973, Fig. 4). The basal plates of the marginals 
of the genus Succinea are intermediate in length 
(Quick, 1933, Figs. 2, 3; and Franzen, 1959, Fig. 3; 
1971, Fig. 3). 

The Jaw. The amber-colored jaw is illustrated 
in Fig. 3, B. Anteriorly the collar has a median 
fold flanked on either side by smaller lateral 
folds. Posteriorly the collar bears a broad, median 
indentation. 

Chromosome Number. Ovotestes of Catinella 
parallela were squashed and stained with orcein. 
Examination of the stained chromosomes in 
meiotic metaphase revealed the haploid number 
of six. This small number is characteristic of the 
genus Catinella (Patterson, 1971, Table 1.). This 
contrasts with the haploid number of nineteen of 
several species of Oxyloma: Oxyloma deprimida 
Franzen (Franzen, 1973, Fig. 1, and p. 68); 0. 
retusa (Lea), 0. haydeni (W. G. Binney) and 0. 
salleana (Pfeiffer) (Franzen, 1966, p. 67). The 
haploid chromosome number of eighteen is char- 
acteristic of Succinea vaginacontorta Lee 
(Franzen, 1971, p. 141) and other species of Siw- 
cinea of continental USA. (Patterson, 1971, Table 

1). 

Geographic Distribution and Habitats. The 
known geographic range of Catinella parallela ex- 
tends from the flood plain of the Illinois River in 
Greene and Jersey counties in western Illinois, 
across the state to the banks of the Wabash River 
in White County in eastern Dlinois, and to Knox 
County in western Indiana. The eight localities 
where I have found C parallela represent three 
types of ecological habitats, namely: (1) a wooded 
flood plain of a river; (2) a slough with stands of 
plants including Typha sp. (cattails), Sagittaria 
latifolia Willd. (arrowhead), Eleocharis sp. (spike 



rush). Polygonum ineum Muhl (water smart- 
weed), Rhus radicans L. (poison ivy), and Spar- 
tina sp. (sawgrass); (3) roadside ditch supporting 
a stand of Typha sp. 

Locality 1, Type Locality: Field No. D.S.F. 458; 
western edge of the flood plain of the west side of 
the Wabash River, below the bridge of Illinois 
Hwy. 14 (formerly U.S. Hwy 460), 7 miles E 
Crossville, White County, Illinois. The flood plain 
is a woodland of predominantly Acer sac- 
charinum L. (silver maple), Gleditsia triacanthos 
L. (honey locust), and Populus deltoides Marsh 
(cottonwood). Catinella parallela lives on the 
shaded damp ground, on rotting wood, and on 
dead leaves on the ground. 

Locality 2, Field No. D.S.F. 459; twelve miles E 
Princeton, Gibson County, Indiana, Indiana Hwy. 
64, one-half mile E Wabash River, in a lowland 
wooded area of predominantly Acer saccharinum 
L. One individual of Catinella parallela was 
under a piece of cardboard in a small pile of rub- 
bish. 

Locality 3, Field No. D.S.F. 460; flood plain of 
the Patoka River, Patoka, Gibson County, In- 
diana, in a wooded area of predominantly Acer 
saccharinum L. and Populus deltoides Marsh. 
Two individuals of Catinella parallela were found 
on damp ground of an exposed area. 

Locality U, Field No. D.S.F. 461; one-half mile 
N White River, a roadside ditch and slough 
alongside Orville Road, west off of U.S. Hwy. 41, 
Knox County, Indiana. Typha sp. grows in the 




mm 





FIG. 3. k: Rfspresentative radvla teeth o/ Catinella parallela 
/(. sp. C, central tooth: 1-L-L, Ut left lateml: i-L-L. ith Icjl 
lateral: U-L-L, Uth left lateral: 1-L-M. 1st left marginal: 8- 
L-M. Sth left marginal. B: A jatr o/'Catinella parallela n. sp. 



68 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



water while Sagittaria latifolia Willd. and Spar- 
tina sp. grow in very wet ground. Oxyloma 
salleana (Pfeiffer) lives on the cattails and on 
dead vegetation floating on the water. Catinella 
parallela lives near the water's edge on the base 
of cattails, on the matting of dead vegetation and 
on bare spots on the wet ground shaded by saw- 
grass and leaf litter. 

Locality 5, Field No. D.S.F. 467; ten miles N 
Vincenes, Knox County, Indiana, roadside ditch 
along U.S. Hwy. 41. Although at the time this 
site was visited the water was becoming polluted, 
TjfjAa sp. was growing in the ditch and Catinella 
parallela was still living there. 

Lncalitii 6. Field No. D.S.F. 269; eastern bank 
of the Illinois River at New Hardin, Greene 
County, Illinois. On June 11, 1964, the ground 
was muddy from recent rains. The bank sup- 
ported a thicket of Salix sp. (willows). Oxyloma 
salleana (Pfeiffer) lived on the muddy bank. 
Catinella parallela was found creeping on the wet 
ground, on surfaces of wet boards and other 
debris on the ground along the eastern edge of 
the flood plain away from the shore of the river. 
Since then, as a result of severe storms and 
flooding, the entire flood plain is littered with 
logs, branches and other debris. The habitats of 
the two succineid species are destroyed, at least 
temporarily. 

Locality 7, Field No. D.S.F. 445; eight-tenths 
mile S Nutwood, or 2.4 miles S from the junction 
of Illinois Hwy. 100 and Illinois Hwy. 16, Jersey 
County, Illinois, on the west side of Illinois Hwy. 
100. The habitat is a poorly drained slough. The 
bottom of the slough consists of fine, tan sand, 
and coarse, sandy reddish-tan loess from the 
deposit immediately to the east. The slough sup- 
ports growths of Typha sp., Eleocharis sp., 
Polygoneum ineum Muhl and RMis radicans L. 
Several small clumps of Popuhis deltoides Marsh 
and a thicket of Comus drummondi C. A. Meyer 
are located within the slough. On June 1, 1975, a 
large population of Oxyloma salleana (Pfeiffer) 
lived on Ti/i)ha sp. and on the wet ground at the 
base of the cattails. A well-establi.shed population 
of Catinella parallela lived on the eastern edge of 
the slough on wet, but not swampy, ground where 
the vegetation was less dense. One June 11, 1977, 



due to an abnormally low amount of rainfall dur- 
ing the spring months, there was no water in the 
slough but the ground was still damp. 0. salleana 
was feeding on cattails and spike rish. However, 
a four-hour search netted only one individual of 
r. parallela. This might indicate that C parallela 
is more readily affected by adverse conditions 
than is (). salleana. 

Locality 8, Field No. D.S.F. 187; Pere Mar- 
quette State Park, Jersey County, Illinois, west 
side of Illinois Hwy. 100. The site is the east 
shore of a lake formed by a bow of the Illinois 
River. On June 15, 1954, Oxyloma salleana (Pfeif- 
fer) and Catinella parallela were abundant on the 
wet ground and on wet boards lying on the bank. 
I have visited this site several times but have not 
found C parallela since 1954, although 0. 
salleana is still well-established. 

Diagnostic Features. Shell: the elongate-ovate 
shell is comprised of 3''4 to 3' : tumid whorls. The 
height of the ovate aperture exceeds six-tenths of 
the height of the shell. Two examples of the latter 
are: (a) The height of the shell of the holotype is 
10.0 mm and its aperture 6.7 mm in height ; height 
of aperture / height of shell is .67. (b) The height of 
the largest shell of the series studied is 15.2 mm 
and its aperture 9.6 mm in height ; height of aper- 
ture / height of shell is .632. The amber-colored 
columella forms the inner border of the peristome. 
A thin callus is discernible on the ultimate whorl 
above the aperture. 

Penis and Penial Appendage: the base of the 
penial appendage equals almost half the length of 
the penis. The expanded appendage is positioned 
parallel to the penis. The vertical dimension of 
the appendage is almost twice the width of the 
body of the penis. The penial retractor muscle 
inserts mainly onto the base of the i^enial appen- 
dage and by means of lesser fibers onto the penis 
andtheepiphallus. 

The specific name parallela refers to the ex- 
panded penial appendage being parallel to the 
penis instead of right angle to the penis as is 
characteristic of other species in the genus 

Catinella. 

Spermatheca: the globular spermatheca is con- 
nected to the vagina by a stout duct which en- 
larges as it approaches and enters the vagina. 



Vol. 9:1 (2-3) 



April 2:1 1979 



THP] NAUTILUS 69 



Comparative Remarks: ('(it'meUn piimUcla 
probably more nearly resembles C. texana 
Hubricht than any other described species. The 
differences include: (a) Shell dimensions and 
ratios of dimensions. (1) The aperture of C. 
parallela is larger in proportion to the height of 
the shell than it is in C. texana. (2) The largest 
known shell of C. parallela is 15.2 mm in height, 
(b) The penial appendage of C. parallela is 
parallel to the penis whereas in C. texana the 
penial appendage is vertical in position, i.e. at 
right angle to the penis, (c) The penial retractor 
muscle of C. parallela inserts mainly onto the 
base of the penial appendage; lesser fibers insert 
onto the penis and onto the epiphallus. The peni- 
al retractor muscle of C. texana is "connected to 
the side of the penis near the middle" (Hubricht, 
1961, p. 61). (e) The spermathecal duct of C. 
parallela is stout, of C. texana slender, (f) The 
seminal vesicle of C. parallela is pigmented but 
not as darkly as described of C. texana as being 
"strongly pigmented, almost black" (ibid). 

ACKNOWLEDGMENTS 

National Science Foundation Grants-in-Aid 
No's. NSF G18000 and NSF GB2715 provided 
laboratory equipment and supported, in part, the 
field studies. Dr. A. Byron Leonard read the 
manuscript and offered helpful suggestions. 



LITERATURE CITED 

Franzen, Dorothea S. 1959. Anatomy of Sitccinea ovdis Say. 

Pmc. Mai. Soc. Lmidon 33(5, Nov.) : 193-199, tables 1-2, figs. 

1-7. 
. 1963. Variations in the Anatomy of the Succineid 

Gastropod Ozyloma retiisa. The Nautilvs 76(3): 82-95. tables 

1-2, figs. 1-4. 

1966. Anatomy of the Succineid Gastropod Ox- 



yloma salleana (Pfeiffer) The Nautilus 80(2): 59-69, tables 
1-2, figs. 1-3, 

1969. Structural Characteristics of Succineid 



Gastropod Oxyloma sanibelensis. The Nautiliix 82(3): 77-83, 
tables 1-3, figs. 1-2. 

. 1971. Anatomy and Geographic Distribution of 



the Succineid Gastropod Suvcinea vaginajcontorta Lee. The 
Nautilus 84(4): 131-142, tables 1-2, figs. 1-3. 

. 1973. Oxylnma deprimida, A New Species of Suc- 



cineidae (Pulmonata). The Nautilvs 87(3): 66-71. tables 1-3, 
figs. 1-a 

Hubricht, Leslie. 1961. Eight New Species of Land Snails from 
the Southern United States. The Nautilus 75(1): 26-33, pi. 4, 
fig. 1; 75(2): 60-61, fig. 2. 

Patters(3n, C. M. 1971. Taxonomic Studies of the Land Snail 
Family Succineidae. Malacological Review 4(2): 131-202. 
tables 1-2, figs. 1-140. 

Pilsbry. Henry A. 1948. Land Mollusca of North America 
(North of Mexico). Acad. Nat. Sci. Philadelphia Monograph 
3, vol. 2. pt. 2: pp.i-xlvii -I- 521-1113, .585 figs. 

Quick, H. E. 1933. The Anatomy of British Succineae. Pmc. 
Mai. Soc. London 20(6): 295-318, pis. 23-25, tables 1-5, figs. 
1-18. 



REDISCOVERY OF SOME PLEUROCERIDS (GASTROPODA) 
NEAR MUSCLE SHOALS, TENNESSEE RIVER, ALABAMA 

Billy G. Isom', Sally D. Dennis^ and Charles Gooch' 



Lithasia verrucosa (Rafinesque, 1820), Lithasia 
geniculata salehrosa (Conrad, 1834), and 
Pleurocera alveare (Conrad, 1854) were 
rediscovered in May 1977 at Muscle Shoals, Ala- 
bama, below Wilson and Wheeler Dams on the 
Tennessee River. 

The last records of L. g. salehrosa from the 



'Tennessee Valley Authority, E&D Building, Muscle Shoals. 
Alabama 35660 

'Tennessee Valley Authority, Forestry Building, Norris, Ten- 
nessee 37828 



Tennessee River, of which the authors are aware, 
was reported by Goodrich (1934). Davis (1974) and 
Stein (1976) presumed that "pure salehrosa is 
probably extinct." However, their statements 
were apparently based on the literature and on 
material collected from the Duck River, but 
neither attempted to sample the original Ten- 
nessee River habitat of this species. L. g. 
salehrosa was found in the tailwater of Wilson 
Dam, the area from which Conrad collected the 
type specimens. 



70 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



Ij. veri-iicond was found in the Tennessee River 
at Florence, Alabama, along the south shore be- 
low U.S. Highway 72 bridge. It undoubtedly oc- 
curs elsewhere in the river, but its total distribu- 
tion is not now known. Historically, this species 
was found in large rivers and large tributaries 
such as the Ohio, Tennessee, Wabash; Black, and 
Spring Rivers in Arkansas (Grwdrich, 1940); Cy- 
press and Flint River tributaries of the Tennessee 
River in Alabama; the Nolichucky River in Ten- 
nessee (Davis, 1974); and other streams. Sinclair 
(1969) indicated that L. verrucosa was limited to 
areas below Kentucky and Pickwick Dams in the 
Tennessee River. 

P. alveare was found just below Wheeler Dam 
on limestone bluff outcrops, generally in water to 
three meters deep. Sinclair (1969) assumed this 
species was killed off by impoundment, while 
Stein (1976) indicated that status of "other" 
populations was unknown. Historically this spe- 
cies was limited, in the Tennessee River, to the 
shoals near Florence, Alabama, and to a number 
of local tributaries, particularly Cypress Creek 
(Goodrich. 1934a, 1934b, 1940, 1941). 

These snails were collected by scuba divers. 
Collection by scuba divers is a very effective 
technique for sampling rock-y substrates, which 



are difficult to sample effectively with conven- 
tional grab samplers. We expect to devehjp addi- 
tional data on these species through the coming 
months. We particularly wish to thank W. Jef- 
frey Pardue and Jimmy G. Walden for their par- 
ticipation in this project. 

LITERATURE CITED 

Davis, George M.. 1974. Report on the Rare and Endangered 
Status of a Selected Number of Freshwater Gastropoda 
from Southeastern U.S.A. For the U. S. Department of the 
Interior, Fish and Wildlife Service, Contract No. 
M018-f)()(l8-766. pp. 32-a5. 

Goodrich, ("alvin, 1934a. Studies of the Gastropcxi Famil.v 
Pleuroceridae-I. C)rr. Paper.'^. Museum of Zoology, University 
of Michigan. No. 286: 17 pages. 1 plate. 

. 1934b. Study of the Gastropod Family 

Pleuroceridae-III. Occ. Papers. Museum of Zoology. Univer- 
sity of Michigan. No. .300: 11 pages. 

. 1940. The Pleuroceridae of the Ohio River 



Drainage System. Occ. Papers. Museum of Zoology. Univer- 
sity of Michigan. No. 417: 21 pages. 

. 1941. Studies of the GastroiX)d Family 

Pleuroceridae-VIII. Or. Papers, Museum of Zoology, 
l.'niversity of Michigan. No. 4-17: 13 pages. 

Sinclair. Ralph M.. 1969. The Pleunx^erid Fauna of the Ten- 
nessee River Gastropoda: Prosobranchia. American 
Malacningical Union, Annual Report: pp. 4.5-47. 

Stein. Carol B., 1976. Gastropods. In: Endangered and 
Threatened Plants and Animals of Alabama. Bull. Alalmmn 
Miiseuni <if Natural Hittury. No. 2, pp. 21-.52. 



A NEW VERTIGO (PULMONATA: PUPILLIDAE) 
FROM THE OZARKIAN UPLIFT 

Amy Shrader Van Devender 

Mollusk Division, Museum of Zoology 

University of Michigan 

Ann Arbor, Michigan 48109 

ABSTRACT 

A new s-pecien of pupillid. Vertigo meramecensis, (.s described from Cniwford 
County. Mii^xonri. It is most similar to Vertigo gouldi and in the sixth Recent 
Vertigo reported from the Noiihern Ozark Plateau. The type locality along Huz- 
zah Creek would be flooded periodically if the proposed dam on the Meramex: 
River is completed. 



On 12 June 1976 five other people and I were 
exploring some wooded limestone bluffs in Craw- 
ford County, Missouri. The site was south of Huz- 



zjih Creek, a few miles south of where it joins 
Courtois Creek which flows into the Meramec 
River nearby. This area lies at the northern edge 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILI'S 71 



of the Ozarkian Uplift (or Ozark Mountains), a 
large plateau covering parts of four states. A 
representative collection of land snails, including 
a new species of VeHigu. was made just after 
dark. The evening was warm and muggy; and 
snails were rommon, actively browsing in the 
plant cover on the bluff face. The tiny Vetiiya. 
found alive, was first seen by Meg LaVal, who 
was using a headlamp to search the mosses and 
lichens on the limestone bluff. 

Malacologists have long found the Ozarks to 
contain an interesting and diverse snail fauna. 
As the literature survey in Reeder and Miles 
(1976) points out, though, collecting has been 
spotty with only a few areas at all well known. It 
is not surprising to note that since Pilsbrj' (1948), 
only Hubricht (1964, 1972) mentions any Voiiyo 
from southern Missouri. 

Vertigo meramecensis, n. sp. 

Figs. la,b: 3b 

Description of Holotype: Shell (Fig. la) oblong, 
tapering with five well-rounded whorls, per- 
forate: 1.86 mm long and 1.15 mm wide, H/D = 
1.82. Shell surface (especially middle whorls) 
strongly, but irregularly striate with embiyonic 
whorls smooth. Shell translucent, chestnut in 
color; lip darker than shell and reflexed with on- 
ly a slight constriction. Penultimate whorl bears 
a crest (Fig. lb) which separates the lip from a 
broad depression external to the palatal teeth 
and extends to just above the middle of the 
whorl. Aperture (Fig. 3b) one third shell length, 
angular, slightly higher than wide. Tooth formula 
1-2-2; subcolumellar weakly developed; all teeth, 
white, situated near the lip edge with lower 
palatal slightly more recessed than the upper; 
parietal in line with the lower palatal. 

Paratypes: Sixteen specimens. Adults (n = 10) 
have a reflexed lip and range in length from 1.72 
mm to 2.01 mm (x = 1.83 ± 0.01) and in width 
from 1.05 mm to 1.20 mm (x = 1.10 ± 0.01). Half 
of the adults lack a subcolumellar lamella 
altogether. The lower palatal is more recessed 
from the lip edge and longer than the upper 
palatal. The lower palatal is variable in length; 
three specimens have the long, slightly cun-ed 
lower palatal shown in Fig. 3b while the fold is 
knob-like in the holot>i)e. This character may de- 
pend on the maturity of the animals. 





FKl. la. Vertigo meramecensis Van Devender, new species. 
Hnti,t>fi>e lUMMZ 2i7l>iO). 1.86 mm. Crawford Co.. Missouri. 
b, Paratiipe (L'MMZ2i76il). 1.87mm. 

Etymology: From the Meramec River drainage 
where the species was collected and the proposed 
Meramec Dam which would periodically flood the 
tyije locality {pers. comm. Dr. R. K. LaVal, 
Missouri Department of Conservation ). 

Types: Holot^^pe, Museum of Zoology, Univer- 
sity of Michigan 247640; 13 paratypes in the 
Museum of Zoology, University of Michigan 
247641; 2 in the Field Museum of Natural His- 
tory and the collection of the author. 

Type Locality: Wooded limestone bluffs above 
Huzzah Creek, 13.8 km E of Steelville, Crawford 
Countv, Missouri (USGS Berrvman 15' NWSW- 
SWNWNE Sec 24, T38N. R3W). 

Discussion: Vertigo memmecenfns belongs in 
the genus VeHigo because of its small size, red- 
brown color, and moderately well-developed teeth. 
Pilsbry (1948: 943-1000) discussed the shell char- 
acters of Vertigo and placed most species in the 
subgenus Vertigo (sensu stricto). He divided the 
subgenus into seven species groups whose compo- 
nent species var>' so widely and overlap so great- 
ly that Pilsbry himself was unable to construct a 
key to them. The new species shares some charac- 
ters with at least two species groups, the Vertigo 
modesta group and the Vertigo gouldi group, but 
seems closest to the Vertigo gouldi group. Pilsbry 
(1948) and Hubricht (1964, 1972) report eight spe- 
cies of Ve^iigo from the northern Ozarks. Of 
these, two are placed in the Vertigo gnuldi 
species group - V. gouldi gouldi and V. hubrichti. 
which was described as a subspecies of V. gouldi 
and is known only from fossil material. 



72 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 




FI(_;. :ia, N'ertigo ijjuldi gduldi (Hitmen). (i'MMZ mil)- 1.9 
ruin. CuinbcrUuid Co.. Maine, b. Vertigo hubrichti Pikhry. 
Paratmw (ANSiP m)S(>2). 2.0.J mm. St. Lmm O,.. Mi^simri. 

Vertigo meramecensis resembles the species 
and subspecies in the V. gouldi group in that it 
has a distinctly striate shell, averages less than 2 
mm long and displays about 5 moderately well- 
developed, white teeth. Unlike the majority of 
members in the species group, it lacks an angular 
lamella and its parietal lamella is directly in line 
with the lower palatal fold. 

Comparisons with the Ozarkian members of the 
V. gouldi group are in order. Vertigo meramecen- 
nis at least superficially resembles the illustra- 
tion in Pilsbry (1948:973, Fig. 521) of the fossil V. 
hubrichti. E.xjimination of four paratypes of Ver- 
tigo gouldi hubrichti (ANSP 160362, Fig. 2b), 
however, shows that V. mprnmprrnsin has a 
smaller, more tapered and more distinctly striate 
shell. While the lower palatal fold of V. hubrichti 
(Fig. 3a) is situated very deeply in the mouth of 
the shell like V. gouldi pamdoxa and V. 



nijliinderi, the palatals of V. mpramecentfis (Fig. 
3h) are close to the lip edge with lower fold only 
slightly more recessed than the upper. The parie- 
tal of V. hubrichti points toward the upper 
rather than the lower palatal fold. The sculpture 
of Vertigo meramecensis is heavier and more ir- 
regular than in Vertigo gouldi gouldi (Fig. 2a) 
and V. meramecensis with smaller teeth has a 
more open aperture than V. gouldi. The parietal 
tooth especially is less massive and straighter 
than in V. gouldi (Fig. 3c) whose parietal points 
between its palatal folds. 

Of the Vertigo species known from outside the 
Ozarks, V. meramecensis most closely resembles 
the illustrations of Vertigo gouldi cristata from 
Eastern Canada (Pilsbry 1948:967-4,5). Compar- 
isons with a series of shells from Southern On- 
tario (UMMZ 180213) show that V. meramecenda 
has heavier teeth, a more nearly square aperture, 
a darker (redder) color and a weaker crest than 
cristata. Vertigo meramecensis sometimes has the 
subcolumellar (basal) lamella that never occurs in 
V. g. cristota. 

Land snails collected with Vertigo meramecen- 
sis include Anguispira alternata (1), Glphi/alinia 
iudentata (2), Mesodon thyroidus (1). Mcsodou 
zaletiis (18), Triodopsis fosteri (39), and Triodop- 
•s/.s- albolabns (5). 

ACKNOWLEDGMENTS 

The scanning electron micrographs were taken 
by the author with the help and advice from the 
staff of the SEM Laboratory, Department of 
Metallurgy and Dr. Alex Tompa, Museum of 
Zoology, University of Michigan. Dr. Tompa and 




FIG. :?a, Verlifci) hubrichti PilKhrii. Pmatinx' IA.\'SP lno.UiJ). 
Enlanjnuent of aperture, r. l.^.i X. b. Vertigo meramecensis 
Win I )e re litter, neie xperiex. Parat iflte fl'MMZ i.',7l>ill. Aper- 



ture irith siiheiiliiiKellar ItiiiieUiu e. lJ,.'i X. c, Vertigo gouldi 
gouldi (Binneij) (i'MMZ iJ.iJlJ. Enlargement of aperture, e. 
l.',r, X. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 73 



Dr. J. B. Burch (l)oth UMMZ) and Dr. Georpe M. 
Davis (ANSP) kindly let me e.xamine and take 
micrographs of material in their care. I want to 
thank Mep and Richard LaVal and Richard W. 
Fullington who read early drafts of the manu- 
script. Special thanks to R. W. Van Devender, 
Leslie Hubricht. and J. B. Burch who each in his 
ow-n way encouraged me to wi-ite this paper. 



LITERATURE CITED 

Hubricht. Leslie. 1964. Some Plei.sti>cene Land Snail Records 

from Missouri and Illinois. S^fWi-iV/zja. (13): 7-17. 
1972. Land Snail Reairds from Missouri. 

Sterkiana, (45): 34-^5. 
Pilsbn', Henry A. 1948. Land Mollusca of North America 

(North of Mexico). Mimdyniph Aiwl. \ul. Sri. Philadelphia 

3. 2(2): 868-1018. 
Reeder. Richard L. and Charles D. Miles. 1976. Land Snails 

from Northern Missouri. SferWano, (61): 15-18. 



OBSERVATIONS ON THE FINGERNAIL CLAM, MUSCULIUM PARTUMEIUM 

(PISIDIIDAE), AND ITS ASSOCIATION WITH THE INTRODUCED 

ASIATIC CLAM, CORBICULA FLUMINEA 

Alton C. Boozer and P. E. Mirkes 

Department of Environmental Science, School of Public Health 

Belle W. Baruch Institute for Marine Biologv' and 

Coastal Research, and The Department of Biology 

University of South Carolina 

Columbia, South Carolina 29208 

ABSTRACT 
In the cooling water system at the ERDA Savannah River Plant, the introduced 
Asiatic clam, Corbicula fluminea, is inhabiting the floor of the sedimentation basin 
and is contributing to fouling problems. A second species of bivalves, the fing email 
clam, Musculium partumeium, permanently inhabits the wall of the basin by 
means of a byssal-like attachment. The possibility of spatial competition between 
these two bivalves is discussed with emphasis on ok^ervations on reproduction. It 
is concluded that because of physiological adaptability M. partumeium can coexist 
with Corbicula. 



The Asiatic clam, Corbicula fluminea (Muller)', 
was first reported in the United States in 1938 in 
the Columbia River of Washington State (Ingram, 
1959). By 1963, Corbicula had spread into the 
Mississippi and Gulf of Mexico Drainage, as evi- 
denced by the Ohio River and Tennessee River 
discoveries (Sinclair and Ingram, 1961; Keup et 
ai. 1963). Sinclair (1971) excluded the Atlantic 
Slope region from the known range of Corbicula 
until Sickel (1973) reported that the exotic clam 

' This species is called Corbicula manilensis Philippi by many 
workers, but we prefer to use the earlier name, fluminea 
(Muller). 



had probably been introduced to the Altamaha 
River of the Southern Atlantic Slope region of 
Georgia in 1968 or 1969. Fuller and Powell (1973) 
reported Corbieida in the Savannah River and 
Delaware River. Diaz (1974) found Corbicula in 
the James River, Virginia, and more recently, 
Rodgers et al., (1977) reported Corbicula in the 
New River, Virginia. 

During the course of its range extension, Cor- 
bicula has caused a dramatic increase in water 
use interference. Ingram (1959) reported Cor- 
bicula fouling problems in California, as did 



74 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



Sinclair (1964) in Tennessee. After the introduc- 
tion of Corbicula in the Savannah River, a 
similar fouling problem developed at the United 
States Energy Research and Development Ad- 
ministration's (ERDA) Savannah River Plant. 
Openings in a plate from a non-reactor cooling 
process were clogged with adult Corbicula shells, 
thus restricting water flow (Tilly, 1976; pergonal 
communication). 

Fouling caused by the Corbicula invasion is not 
the only concern of investigators. The possibility 
of a drastic impact on other bivalves has been of 
great concern to biologists. Sickel (1973) observed 
that where Corbicula were most dense in the 
Altamaha River, Georgia, there were no union ids, 
although the habitat appeared suitable. Gardner 
et al. (1976) determined that the invasion of Cor- 
bicula in the Altamaha River had been ac- 
companied by a drastic decline in the populations 
of other bivalves (Pisidiidae and some Union- 
idae). 

During Ccrrbicula fouling studies at the ERDA 
Savannah River Plant, a sedimentation basin of a 
water treatment plant was found to contain two 
dominant species of bivalves. One of the species 
was Corbicula fluminea (Miiller), the other 
species was Musculium partumeium (Say). 
Earlier studies had shown that the Corbicula in- 
vasion had had an impact upon other bivalves. 
This study deals with the association between M. 
partumeium and Corbicula. 

Description of Study Area 

The study area is located within the designated 
4(X) area of the U.S. Energy Research and 
Development Administration's (ERDA) Savannah 
River Plant. A water intake structure is located 
on the Savannah River from which water is 
pumped through a closed pipe to the 400 area 
water treatment plant. Water is first received at 
the plant in a sedimentation basin. From this 
point, a portion of the water receives additional 
treatment for extensive use in the 400 area. The 
larger portion of incoming water receives little 
treatment and is used as cooling water in a non- 
reactor cooling process. It was in this cooling pro- 
cess that Corbicula fouling was first observed. A 
subsequent investigation lead to the discovery 



that the sedimentation basin had become a per- 
manent habitat for freshwater clam populations 
of both Corbicula and M. partumeium. 

The sedimentation basin consists of concrete 
bottom and walls. The bottom of the basin is 
covered with an extensive amount of mud, silt, 
and sand from the settling process. Due to the 
sediment buildup, the depth of the basin ranges 
from 4 to 8 feet with an average depth of 5 feet. 
An excellent substrate has developed for macro- 
invertebrates, since the basin has not been 
cleaned in at least eight years. Water remains at 
a fixed level in the basin throughout the year, 
thus allowing some organisms to inhabit the con- 
crete walls of the basin. It was decided that since 
fouling problems had originated in the sedimen- 
tation basin, specimens would be collected from 
that area. 

Additional sampling was attempted in the 
Savannah River adjacent to the Savannah River 
Plant property. Water fluctuation resulting from 
the Clark Hill Reservoir Hydroelectric Plant 
made river access difficult, and therefore sam- 
pling was abandoned. 

Materials and Methods 

Qualitative samples were taken monthly from 
the 400 area sedimentation basin from January, 
1976, through July, 1976, including a semi-monthly 
sample in June, 1976. Samples of Corbicula were 
obtained by scooping the clams from the bottom of 
the basin with a commercial clam shovel. Samples 
were collected from the walls of the basin with a 
plankton net (25 micron). The net was lowered to 
the substrate-water interface beside the wall and 
then dravTO up the side of the wall toward the 
water surface. An effort was made to take approx- 
imately the same amount of material each time 
since careful quantitative measurement was not 
possible. Samples were placed in styrofoam coolers 
containing aerated river water and returned to the 
laboratory for careful sorting so that the young 
would not be overlooked. 

Numerous gross dissections were made under a 
binocular scope and many observations were made 
upon young and transparent specimens under a 
compound microscope. A sub-sample of 30 of the 
fingernail clams, M. partumeium. was taken from 
each of the April, May and June collections for 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 75 



determination of approximate brood sizes for iden- 
tification purposes. The left and right inner 
demibranches of the gills were excised from each 
parent, and enclosed larvae were counted and 
measured for length with the aid of an ocular 
micrometer. Unfortunately, because of the nature 
of the collecting method employed, it was impossi- 
ble to determine whether some or all of the extra- 
marsupial larvae had been prematurely born or 
aborted, with the result that the number of in- 
cubating larvae found upon dissection may have 
been misleadingly low. Determinations were made 
to approximate size classes for developmental 
stages of M partumeium larvae. 

During August, 1976 the study was abruptly 
halted when collections indicated that a complete 
kill of both species of clams had occurred. Post- 
chlorination facilities at the water treatment plant 
had become inoperable, leading to emergency pre- 
chlorination of water prior to its entry in the 
sedimentation basin. Malfunction of the pre- 
chlorination equipment allowed excessive levels of 
chlorine to enter the basin for a period of several 
days, thus resulting in the kill. 

A collection of Corbicula was made in the Savan- 
nah River on August 26, 1976 to check for gravidity. 
An attempt was made to collect M. partumeium. 
but none were found. Since Corbicula in the Savan- 
nah River were incubating young, qualitative and 
quantitative samples were collected from the 
sedimentation basin in January and April, 1977, to 
determine if repopulation was occurring through 
recruitment from the Savannah River. The quali- 
tative samples were collected from the wall of the 
basin as described previously. Quantitative 
samples of the bottom material were made with a 
standard Ekman dredge. All of these collections 
were preserved immediately in 70 percent ethanol 
and returned to the laboratory. Clams were iden- 
tified and counted, and some sf)ecimens were mea- 
sured for length (anterior to posterior) with an 
ocular micrometer. 

Results and Discussion 

Taxonomy 

The superfamily Corbiculacea Gray, 1847 is 
represented in North America by 37 species of the 
family Pisidiidae Gray, 1857 (formerly Sphaeri- 
idae, Jeffreys, 1862), and by one introduced species 



(Corbicula fluminea) of the cosmopolitan family 
{x)rbiculidae (Burch, 1975). The Pisidiidae contain 
the five genera Sphaerium, Musculium, Pmdium, 
Byssanodonta, and Eupera. Baker (1927) divided 
the family into two subfamilies, based on the char- 
acters of the siphons. Heard (1965) later found 
enough differences to warrant three separate sub- 
families, distinguishable on the basis of the nature 
of their siphonal arrangement and development of 
their embryos. The subfamilies are Sphaeninae, 
containing the genera Sphaerium and Musculium.; 
Pisidiinae. containing the genus Pisidium; and 
Euperinae. containing the genus Eupera (Burch, 
1975). 

In North America there are eight species of 
Sphaerium and four species of Musculium (Burch, 
1975). One of the characteristics used to justify the 
validity of Musculium as a genus was the presence 
of a calyculus or "cap" at the umbone. Sterki (1909) 
found, however, that in most species of Musculium. 
specimens are found with slightly or noncalyculate 
beaks and that calyculate beaks are found occa- 
sionally in specimens of Pisidium and Sphaerium. 
Herrington (1962) suggested that calyculi have lit- 
tle taxonomic value because he, too, witnessed their 
occurrence in groups other than Musculium. He 
concluded Musculium to be a synonym, or at most a 
subgenus, of Sphaerium because of the lack of 
significant diagnostic shell characteristics to dis- 
tinguish the two. When Gale (1972) determined 
that arrested growth caused the formation of a 
calyculus, he further questioned the taxonomic im- 
portance of this character. Studies on calyculate 
and uncalyculate forms of Mu.sculium securis 
(Prime) by Mackie and Qadri (1974) indicated that 
calyculism is a predictable feature, and that the 
so-called "caps" of Sphaerium species are probably 
"pseudocalyculae". True calyculae are separated 
from adult valves by a sulcus, but "pseudocaly- 
culae" are separated by an annulus. The calyculate 
character is of significance in identifying different 
generations in Musculium populations. 

More recently. Heard (1977) has indicated that 
Musculium is a valid genus on the basis of several 
life history aspects. He concluded that: (1) propor- 
tionately more species of Musculium can inhabit 
temporary ponds than species of Sphaerium; (2) the 
extra-marsupial larvae of all knovra species lack 



76 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



eggs and sperm, which are found in the larvae in 
most species of Sphaerium; (3) all known species of 
this group show a higher fecundity, in terms of to- 
tal numbers of young produced, than do most spe- 
cies of Sphaerium: (4) its species in general appear 
to have a shorter life cycle (30-70 days) than do 
Sphaerium spp. (4-8 months); (5) individuals of this 
group may have a shorter life span than do those of 
most species of Sphaerium: and (6) the two siphons 
in Musculium are fused together in their basal 
halves only, whereas, those in Sphaerium are fused 
together for their entire length. In addition, the 
shelled larvae in the gills of all Musculium species 
and Sphaerium comeum and Sphaerium occiden- 
tale are anchored by a byssal thread to a common 
stalk. Heard (1977) further noted that S comeum 
and S. occidentale occupy a comparatively in- 
termediate position between the two genera, shar- 
ing a number of features of both groups (see Table 
1). These two species have traditionally been placed 
in Sphaerium, either because of their lack of 
calyculated beaks or because of the degree of siphon 
fusion. 



From observations on anatomy, e.xpected 
habitat, and life histor\' of the pisidiids. and up<in 
comparison with features presented in Table 1 and 
the preceding discussion, the clam inhabiting the 
sedimentation basin was determined to be of the 
genus Musadium. Although characters of soft 
anatomy are used in taxonomy of the Corbiculacea, 
especially in the classification to the generic 
level, all taxa can be identified by characters of 
the shells, and such shell characteristics are par- 
ticularly important in distinguishing the species 
(Burch, 1975). Considering characters of the shell, 
habitat, and range, the pisidiid in this study was 
identified as Musculium partumeium (Say). A 
description of the key shell characteristics follows: 
Hinge of smooth lateral teeth ; beaks of shell 
located centrally or anterior of center; shell with 
two cardinal teeth in one valve, and one in the 
opposing valve; shell sculptured with fine striae; 
adult shell small, less than 8 mm in length; 
posterior end nearly at right angles to the dorsal 
margin ; anterior ventral margin of shell slopes 
upward, but only slightly; surface glossy (Burch, 
1975). 



TABLE 1. Comparison o/Sphaerium corneum. Sphiierium ix-ddentale. "?/ipr Sphaerium. and Masculium (Heard. 1S7T). 



Feature 


S. corneum 


Siphon fusion 




entire 


+ 


partial 




Standing water 




permanent 


+ 


temporary 




Mature gametes in extra 




marsupial larvae 


+ 


Functional byssus in 




late larvae 


+ 


Number of F/^ per sac 




few 


+ 


many 




Size of newborn 




small 




large 


+ 



S. corneum S. occidentale Sphaerium 



Musculium 



F, - a collective designation given fur all incubatinp young regardless of stage of development. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 77 



M. partumeium is distributed throughout the 
United States and in southern Canada from New 
Brunswick to Saskatchewan (Herrington, 1962). Its 
habitat includes mud bottoms in small lakes, 
ponds, and swamps, and lotic situations. Clarke 
(1973) also found its habitat to include muddy parts 
of large lakes in the Canadian Interior Basin, as 
well as vernal ponds. Baker (1928) found it in black 
mud in shallow water of stable and temporary 
ponds. 

Little will be included here concerning the tax- 
onomy of Corhicula fluminea in this study. Sinclair 
and Isom (1963) have documented this subject fully 
in an earlier report. Corbicula from the 400 area 
sedimentation basin and the Savannah River was 
easily identified by the presence of three cardinal 
teeth per valve, the serrated lateral teeth, and the 
ribbed appearance of the shell (Sinclair and Isom, 
1963). Corbicula manilensis Philippi is considered 
by us to be a synonym. 

Attachment inM. partumeium (Say). 

Identifications performed on the qualitative 
samples collected from the wall of the 400 area 
basin during the January through June 1976 collec- 
tions, revealed that a population of the fingernail 
clam, M. partum£ium, was inhabiting the wall of 
the sedimentation basin. From on-site visual ex- 
amination of the samples, it appeared that the 
clams were actually attached to the wall and not 
burrowed under the thin layer of oligochaetes on 
the wall. Live specimens, after being sorted from 
oligochaetes and debris and being placed in glass 
aquaria in the laboratory, could readily climb the 
vertical walls of the container and attach to the 
glass. The foot of the clam is used in climbing but 
once the clam is on the vertical surface, threadlike 
filaments allow the clam's valves to remain closed 
while the clam is freely suspended from the side of 
the glass. Shell lengths of the M. partumeium en- 
countered on the wall and observed in the lab- 
oratory ranged from 1.2 mm to 6.2 mm. 

In describing the subfamily Sphaeriinae, Monk 
(1928) noted that the foot is anchored by means of 
an expansion of the anterior tip and ventral side. 
Adhesion is facilitated by a mucus secretion from 
the mucus glands of the foot. He noted that the 
mucus secretion is an important means of anchor- 
ing the foot, and that young specimens could climb 



vertical surfaces by this aid alone. Monk (1928) ad- 
ded that the byssal gland is vestigial in Sphaeri- 
inae. The gland is much larger in the embryo, but 
the duct that supplies the gland is already occluded 
in embryos 1 mm or less in length. In contrast, 
Baker (1928) stated that while the adults usually 
bury themselves in the bottom, the young may be 
very active, crawling over plants and even suspend- 
ing themselves from plants by byssal threads, thus 
suggesting a functional byssal gland. 

When Heard (1965) divided the Pisidiidae into 
three subfamilies, he stated that Euperinae 
possess a functional byssal gland, whereas Sphae- 
riinae (Sphaerium and MusculiumJ and Pisidii- 
nac did not. Byssanodonta. another pisidiid, lim- 
ited in distribution to South America, is known 
to have a functional byssal gland. More recently, 
Heard (1977) has reported that a functional 
larval byssus occurs in all North American 
species of Miisculium, Sphaerium ocddentale 
(Prime), and Sphaerium comeum (Linnaeus). The 
byssus is evident in the shelled larvae (prodisso- 
conch and extra-marsupial development stages) 
and is believed to function in the prevention of 
precocious birth (abortion) until the larval gonads 
sexually mature (Heard, 1977). Mackie et. al, 
(1974a) described the structure of the larval 
byssus of Musculium securis (Prime) as consisting 
of a byssal stalk that originates in the foot of the 
prodissoconch larvae and a byssal bulb that in- 
serts on the descending lamella of the inner gill 
of the parent. In this study, dissection of gills of 
M. partumeium collected from the sedimentation 
basin revealed the presence of the byssal stalk 
and byssal bulb on prodissoconch and some extra- 
marsupial larvae. 

In reviewing the significance of the byssus in 
bivalves, Yonge (1962) stated that in cases where 
the byssus is retained for permanent attachment of 
the adult, it also functions in early life when the 
foot is still active as an organ of temporary attach- 
ment. By this means, the young bivalve climbs ver- 
tical surfaces. He added that, in general, wherever 
a functional byssal apparatus is present it is ob- 
viously related to a change in habit from infaunal 
to epifaunal life. Yonge (1962) concluded that the 
presence of a byssal apparatus in the adult 



78 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



represents the persistence of a post-larval organ. 
i.e., that the animals possessing it are in this 
respect neotenous. 

The functional larval byssus, the epifaunal hab- 
itat of the clams on the basin wall as well as the 
record of vertical attachment, all suggest a func- 
tional byssus in adult M. partumeium. Whether the 
byssal-like attachment by thread derives from a 
functional byssus or by mucus secretions from the 
foot is uncertain. However. M. partumeium does 
have a method of attachment allowing it to inhabit 
the wall of a basin throughout its lifetime. 

Notes on Reproductum. 

During the course of this study, some observa- 
tions on reproduction in M. partumeium were 
made, mainly for the purpose of identification of 
the species but also to note any major changes in 
reproductive habit associated with byssal-like at- 
tachment to the wall of the sedimentation basin. 
Observations on reproduction in Corbicula were 
included. 

Like all Sphaeriinae, M. partumeium is 
monoecious and ovoviviparous; it is self-fertil- 
izing internally (Thomas, 1959). Fertilized eggs 
are retained and incubated within the body of 
the parent, and development of the embryos takes 
place in the marsupial or brood sacs formed by 
the inner (anterior) gills. Gilmore (1917) and 
Mackie et at.. (1974b) have described the struc- 
ture and development of such brood sacs in cer- 
tain species of Sphaeriinae. In his division of the 
Pisidiidae into 3 subfamilies, Heard (1965) used 
as a distinguishing characteristic the fact that in 
Sphaeriinae the embryos develop in several thin- 
walled longitudinal sacs in each anterior gill, 
each sac containing one or more embryos. 

Observations on samples collected from the sed- 
imentation basin during January through July, 
1976, and January and April, 1977, revealed that 
some M. partumeium were brooding extra - 
marsupial larvae in the gills during each collec- 
tion. A peak in number of young ranging in size 
from 1.3-2.0 mm was evident in the June 10, 1976 
sample and the January, 1976 and 1977 samples. 
All clams collected were not size classed, but the 
January and June peaks in number of young 
were visually evident during field collection and 
laboratory examination. 



Gilmore (1917) and Foster (1932) reported that 
reproduction in Sphaerium goes on throughout 
the year, with a preponderance of young at cer- 
tain times of the year. Mackie et al., (1976a) 
found that births occurred throughout the year in 
a population of M. securis collected from a per- 
manent aquatic habitat in Canada. They con- 
cluded from size classes dominating the summer 
collections and from newborn dominating the 
winter population that birth periods occurred in 
early summer and late summer-early autumn in 
the permanent habitat. Thomas (1959, 1963, 1965) 
studied a population of M. partumeium in a tem- 
porary pond and found that the production of the 
first young was seen in June when the pond had 
filled in March. Standing water disappeared from 
the pond in late June, leaving primarily young 
individuals which maintained the clam popula- 
tion over the winter. Mackie et al., (1976b) con- 
cluded from studies on M. securis that in- 
trapopulation variations in reproduction are 
more pronounced in temporar>' than in perma- 
nent aquatic habitats and that reproductive 
habits may be adaptively modified. Heard (1977) 
suggested that fertilization and birth can occur at 
any time in an animal, but, because of relative 
synchronization of individuals, a population can 
display seasonal, peak periods of those activities. 

Dissections of the inner gills of adult M. par- 
tumeium during this study revealed that four 
developmental stages of incubating young (F,) oc- 
curred. These four stages, each arising from a dif- 
ferent time of fertilization, have been described 
by Heard (1977) and Mackie and Huggins (1976) 
as follows: embryos which include all develop- 
mental stages between the zygote and completed 
gastrula; fetal larvae which include all devel- 
opmental stages between the gastrula and the 
beginning of the formation of the shell; pro- 
dissoconch larvae which include all developmen- 
tal stages of shelled larvae while within brood 
sacs; and extra -marsupial larvae which are those 
that have escaped from the brood sacs and lie 
free in the interlamellar space prior to birth or 
are byssally attached to the demibranch. Figure 1 
shows these four developmental stages in M. par- 
tumeium determined by numerous gill dissections 
of adults. General size distinctions were made 
between F, of the four stages of development. The 



Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 79 




FIG. 1. Life history o/Musculium partumeium (Say). Nate the four 
identified asfollous: d, disaocnnch: st, statacyst: ft, /oof,- vm, visceral 

specific duration of incubation of each of the four 
developmental stages is unknown for Sphaerium 
and Mitsculium (Heard, 1977). 

Observations of dissections of live specimens 
indicated that fetal larvae show ciliary action 
similar to that shown by the trochophores of Cor- 
bicitla. Trochophore and veliger stages are sup- 
pressed in M. partumeium, however. The pro- 
dissoconch larvae exhibit direct development with 
continued shell formation until the visceral mass 
is completely enclosed. Internal development 
takes place throughout this period. The visceral 
mass is moved about in the region of the foot 
while development continues. The extra-mar- 
supial larvae show advanced internal structure 
similar to adults. The newly released clams ap- 
pear to be miniatures of the adult. 

The largest extra-marsupial larvae found in 
dissections of M. partumeium were 1.40 mm. 
Heard (1977) found the largest in his studies to 
be 1.22 mm. Thomas (1959) determined a mean 
birth length for M. partumeium in a temporary 



developmental stages and respective size classes. Symbols are 
mass: g, gills: h, heart. 

pond to be 1.6 mm, as compared to 1.44 mm in 
the laboratory. The smallest to be successfully 
raised was one which measured 1.25 mm in 
length. During the June and January sample col- 
lections of this study when young production was 
high, the major size class ranged from 1.3-2.1 
mm. 

The smallest specimen of M. partumeium ex- 
amined that contained any developmental stage 
of larvae was measured at 2.58 mm in length. On- 
ly embryos were present in the brood sac. 
Thomas (1959) reported that ovary and testis are 
present at birth in M partumeium, but neither 
organ contains mature reproductive cells. The 
mean length of the newborn was 1.6 mm, and the 
smallest developing adult that contained gametes 
was 2.1 mm long. Mackie et al., (1976b) found 
gametogenesis first apparent in adult M. securis 
of length 2.00-2.50 mm. They reported simul- 
taneous maturation of gametes as did Thomas 
(1959) for M. partumeium. Heard (1977) stated 
that extra-marsupial larvae of most Sphaerium 



80 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



already contain eggs and sperm, whereas gametes 
are not present in S. occidentale and Musculium 
after birth. 

Unfortunately because of the method by which 
samples were obtained, accurate brood sizes could 
not be determined for M. partumeium. The true 
brood sizes might have been larger than any 
found in this study, since the methodology could 
have led to abortion of extra-marsupial larvae. 
From general observations, it was evident that 
brood sizes were large, with values ranging from 
2 to 33. These data were considered sufficient for 
identification purposes. Gilmore (1917) listed be- 
tween 10 and 20 as the brood size for M. par- 
tumeium, whereas Thomas (1959) reported a 
range of 2 to 30 and a mean of 10 for the same 
species. Heard (1977) found as many as 14 F, per 
brood sac and from 1 to 5 sacs in M. partumeium. 
When dissected, older adult M. partumeium con- 
tained a greater number of F, than younger 
adults. An increase in generative performance 
with age has been reported by Thomas (1959) and 
Heard (1977) for M. partumeium and by Mackie 
et a/., (1976b) for M. securis. 

The life history of Corbicula has been described 
by Sinclair and Isom (1963). Corbicula from the 
Savannah River and the 400 area sedimentation 
basin show similar developmental stages. Of ma- 
jor importance is the fact that Corbicula young 
are released as planktotrophic veligers or benthic 
veligers at a size of approximately 0.22 mm. The 
importance of this will be discussed later. 

Samples of Corbicula collected January-July, 
1976, from the sedimentation basin and August 
25, 1976, from the Savannah River were examined 
for gravidity. Specimens inspected in May and 
early June were incubating veligers in the gill. 
Not until August 25, 1976, were Corbicula again 
found to be gravid. The sample from the Savan- 
nah River, taken adjacent to the 400 area water 
intake, showed Corbicula to be incubating 
trochophore larvae at that time. 

The findings of this study on the reproductive 
period confirm reports in the literature. Sickel 
(1976) examined plankton samples for Corbicula 
larvae in the Altamaha River in Georgia. He 
found larvae present in the water column 
throughout the year, except for the month of 
March, with a peak density in May. Aldridge and 



McMahon (1976) reported that Corbicula have 
two generations per year, a spring reproductive 
period extending from mid-April to late July and 
a fall reproductive period extending from late 
August to late November. They found Corbicula 
from Lake Arlington, Texas, with individual dai- 
ly fecundities of 387.0 veligers/clam and 319.8 
veligers/clam for the spring and fall reproductive 
periods, respectively. 

Repopulation of the Study Area Basin. 

Qualitative samples collected from the wall of 
the sedimentation basin and quantitative samples 
collected from the floor of the basin in January 
and April, 1977 were taken to determine the ex- 
tent of repopulation of the basin following the 
August, 1976, extermination. In January, 1977, 
the wall sample indicated that M. partumeium 
was repopulating the basin. The sample consisted 
of 619 M. partumeium but also 11 Corbicula. 
Sizes of M. partumeium ranged from 1.26 mm to 
6.27 mm long, with a preponderance of 1.3-2.0 
mm long young. The Corbicula ranged in length 
from 1.61 mm to 5.0 mm. An examination of the 
bottom material collected during January, 1977, 
showed M. partumeium concentrations of 
1834/m^ as compared to 856/m^ of Corbicula. More 
numerous in both species were young clams in 
the 1.3-2.0 mm length class. Some specimens of 
both species attained lengths as great as 8.0 mm. 

The results of the April, 1977 sample collec- 
tions differed dramatically from the January 
findings. A similar sampling effort was made in 
the April sample collection from the basin wall 
as was made in the January collection. Results 
showed 3277 M. partumeium in the collection as 
compared to 2 Corbicula. The Corbicula were 2.0 
mm and 2.1 mm long, while the M. partumeium 
showed a complete range of size classes. Ex- 
amination of the April bottom sample revealed 
M. partumeium concentrations of 1320/m^ but 
Corbicula concentrations had increased to 
8200/m^ Corbicula ranged in length from 0.87 to 
13.9 mm with a large number of clams between 
1.0 mm and 7.0 mm. Various sizes of M. par- 
tumeium were collected in the sample, but the 
greatest number were 4.0 mm to 6.0 mm in 
length. 



Vol. 9.3 (2-3) 



April 23, 1979 



THE NAUTILUS 81 



The results of the January and April, 1977 
sample collections indicated that repopulation of 
the sedimentation basin was well underway. 
Since newly released M. partumeium are usually 
at least 1.25 mm long, it would seem that recruit- 
ment from the river may span a wide distribu- 
tion of sizes. Results of the variety of size classes 
present in the January and April, 1977 samples 
would tend to support this belief. In recent imp- 
ingement and entrainment studies at the Savan- 
nah River Plant, it has been determined that not 
only Corbicula veligers but also benthic larvae 
and juveniles are recruited in the water intakes 
(Tilly, 1976; personal communication). Corbicula 
are well-established in the Savannah River near 
the study area. M. partumeium have not been col- 
lected from the river, although the vast Savannah 
River swamp would seem to be an ideal habitat 
for this clam. Lack of collection has probably 
resulted from the inability to put a boat in the 
river at high water and the inaccessibility of the 
swamp when one does get a boat in the river at 
low water. 

The majority of the younger clams present in 
the January, 1977 sample were probably re- 
cruited directly from the river, although some 
might have been bom in the basin from gravid 
clams recruited in the Fall. M. partumeium up to 
8.0 mm in length were present in the January 
sample, as well as some Corbicula of the same 
size. Sinclair and Isom (1963) found Corbicula to 
be sexually mature at a length of 6.5 mm. Some 
reproduction in Corbicula may have been under- 
way by the time of the April, 1977 collection, 
since a large number of 1.0-3.0 mm long clams 
were present, as well as a large number of 4.0-8.0 
mm long Corbicula. M. partumeium appeared to 
be prepared for an early summer reproductive 
period, since most clams ranged in size from 
4.0-6.0 mm long. 

Interactions ofM. partumeium with Corbicula. 

From a comparison of the results of the 
January, 1977 collection and the April, 1977 col- 
lections, the number of Corbicula increased 
dramatically on the floor of the basin while the 
number of M. partumeium decreased somewhat. 
During the same period in which the Corbicula 



|X)pulati()n increased on the floor of the basin, the 
population of M. partumeium increased 
dramatically on the wall of the basin. 

The number of Corbicula collected from the 
wall of the basin in January, 1977, was 11. In the 
April, 1977, collection from the wall, when it ap- 
peared that a much larger population of M. par- 
tumeium was present, only 2 Corbicula were 
found. During the January through July, 1976 
sample collections, no Corbicula specimens were 
found in the established population of M. par- 
tumeium on the wall of the basin. 

M. partumeium and Corbicula are able to co- 
exist in the basin. The byssal-like attachment of 
M partumeium may give this species a com- 
petitive advantage on the basin wall. Such an 
adaptation resulting in a competitive advantage 
is supported by the data of Heard (1977) which 
indicate that a functional larval byssus in S. oc- 
cidentale and M. partumeium is an adaptation 
for temporary habitats. 

Several interactions, such as food or space, may 
make it advantageous for M. partumeium to in- 
habit the wall of the basin by attachment. Spatial 
competition is a likely possibility considering the 
confines of the basin. Sickel (1973) reported that 
in the Altamaha River, Georgia, no unionids 
were present where Corbicula were most dense, 
although the habitat appeared suitable. He stated 
that it was unlikely to be spatial competition 
since the size of Corbicula and its density did not 
appear to be great enough to exclude the much 
larger unionids. Sickel (1976) later reported that 
Corbicula may be excluding the juvenile unionids 
which may eventually result in the loss of ende- 
mic species of clams. This competitive interaction 
would be more closely representative of the situa- 
tion with M. partumeium. Corbicula in the 
sedimentation basin and the Savannah River 
ranged in maximum size from 25 mm to 35 mm 
long. In comparison, M. partumeium collected 
from the basin reached a maximum size of 8.0 
mm in length. 

There also may be spatial competition for the 
wall habitat of the basin. From earlier discus- 
sions, it was shown that Corbicula were present 
in very few numbers in January and April, 1977 
sample collections and not present at all in 



82 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



Januarj'-July, 1976 sample collections although 
the wall of the basin was well populated with M. 
partumeium. Although Corbicula is known to 
have a functional byssus (Sinclair and Isom, 
1963). the size at which the clam is released from 
the gills of the adult would place it at a definite 
disadvantage. As mentioned earlier in the text, 
the veligers of Corbicula measure approximately 
0.22 mm when released. In comparison, M. par- 
tumeium measures approximately 1.3 mm in 
length or larger when released from the gills 
(Figure 1) which would seem to give this clam a 
competitive advantage over the Corbicula larvae 
for the wall habitat, in this case, the preferred 
habitat for M. partumeium. 

Heard (1977), in evaluating fecundity in terms 
of current ecological theory, determined that 
Musculium and S. occidentale are "r-strategists" 
in ephemeral habitats, devoting more energy to 
reproduction. In contrast, other Sphaerium and 
Pisidium in perennial habitats are "k- 
strategists," expending greater energy on such 
non-reproductive activities as maintenance. 

Corbicula is an introduced species to the 
United States and shows characteristics of both 
an "r-strategist" and a "k-strategist." The "r- 
strategies" employed by Corbicula include early 
reproductive maturity and high fecundity. The 
"k-strategies" include producing young that have 
a greater survival probability, a long life span, 
and energy for competition. It appears that M. 
partumeium, normally an "r-strategist" in 
ephemeral habitats, may exhibit more "k- 
strategies" in the permanent aquatic habitat of 
the basin and thus may be using more of the 
available energy for competition. Heard (1977) 
reported that where Pisidium and Sphaerium 
both exist in the littoral zone of lakes, the range 
of the "r-strategist" Pisidium extended into the 
profundal zone, because of interactions with the 
more competitive Sphaerium. 

CONCLUSIONS 

Musculium partumeium has retained some lar- 
val form of byssal-like attachment throughout its 
lifetime which enables it to inhabit the wall of 
the 400 area sedimentation basin. It is not known 



whether the attachment originates from a func- 
tional byssus or from mucus secretions of the 
foot. 

Some interaction or competition may exist be- 
tween M. partumeium and Corbicula. Spatial 
competition is considered highly probable because 
of the size differences between adult Corbicula 
and adult M. partumeium. With the much larger 
size, adult Corbicula may inhabit the preferred 
habitat of the basin floor. In a like manner, M. 
partumeium may spatially out-compete young 
Corbicula for the habitat of the basin wall, since 
both species are capable of byssal attachment. 
Newly released M. partumeium are much larger 
than the Corbicula veligers and therefore may oc- 
cupy the wall habitat, in this case, the preferred 
habitat for M. partumeium. 

Observations on M. partumeium collected from 
the basin wall did not reveal any major changes 
in reproductive habits. It would be extremely dif- 
ficult to document any minor variation in repro- 
ductive habits, since such habits are adaptively 
modified by changes in environment or habitat. 

It is concluded that the adaptability of M. par- 
tumeium may have made it possible for the clam 
to coexist in the sedimentation basin with Cor- 
bicula. Those species capable of inhabiting tem- 
f)orary habitats may possess the adaptability 
necessary to withstand the Corbicula invasion. 

ACKNOWLEDGMENTS 

This research was supported by E. I. DuPont 
de Nemours and Company, Savannah River 
Laboratory, through a grant awarded to the 
University of South Carolina School of Public 
Health. This work was submitted in partial 
fulfillment of the degree of Masters of Science in 
Public Health. 



LITERATURE CITED 

Aldridfje, D. W. and R. F. McMahon. 1976. Population growth 
and reproduction in the Hfe-cycle of Corbicula mmiilensk 
Philippi. As abstracted in Corbicula Newsletter, ed. J. S. 
Mattice. Oak Ridge National Laboratory. Vol. 1 (4). 1976. 

Baker, F. C. 1927. On the division of the Sphaeriidae into two 
subfamilies: and the description of a new genus of 
Unionidae, with descriptions of new varieties. American 
midland Naturalist 10: 220-223. 



Vol. 93 (2-3) 



April 2.'^, 1979 



THE NAUTILUS 83 



. 1928. The Freshwater Mollusca of Wisconsin. 

Part 2. Bull. 70, Wis. Geol. and Natural History Survey 

Ser. 1527: x.x + 507p (p310-429). 
Burch, J. B. 1975. Freshwater Sphaeriaeean Clams (Mollusca: 

Pelecifiioda) of North America. Malacologicai Publications, 

Hamburg, Michigan. 
Clarke. Arthur H. 1973. The freshwater molluscs of the Cana- 
dian Interior Basin. Malacoloyia 13: 1-509. 
Diaz, R. J. 1974. Asiatic clam, Corbicula manilensis (Philippi) 

in the tidal James River, Virginia. Chesapeake Science 15: 

118-120. 
Foster. T. D. 1932. Observations on the life history of a finger- 
nail shell of the genus Sp/iwn'(/7n. •/ Murph. 53: 473-497. 
Fuller, S. L. H. and C. E. Powell 1973. Range extensions of 

Corbimla manilensis (Philippi) in the Atlantic drainage of 

the United States. The Nautilus 87(2): 59. 
Gale, W F. 1972. Seasonal variability in calyculism in 

Sphaerium transversum (Say). The Nautilus 86(1): 20-22. 
Gardner, J. A., Jr., W. R. Woodall, Jr., A. A. Staats, Jr., and 

J. F. Napoli. 1976. The invasion of the Asiatic clam (Cor- 
bicula manilensis Philippi) in the Altamaha River, Georgia. 

The Nautilus 90{3): 117-125. 
Gilmore, R. J. 1917. Notes on reproduction and growth in cer- 
tain viviparous mussels of the family Sphaeriidae. The 

Nautilus 31: 16-30. 
Heard, W. H. 1965. Recent Eupera (Pelecypoda: Sphaeriidae) 

in the United States. American midland Naturalist 74(2): 

309-317. 
. 1977. Reproduction of fingernail clams 

(Sphaeriidae: Sphaerium and Musculium). Malacologia 

16(2): 421-455. 
Herrington, H. B. 1962. A revision of the Sphaeriidae of 

North America (Mollusca: Pelecypoda). Misc. Pubis. Mus. 

ZooL. Univ. Mich. 118: 1-74. 
Ingram, W. M. 1959. Asiatic clams as potential pests in 

California water supplies. Jour. A WWA 51(3): 363-370. 
Keup, L., W. B. Horning, and W. M. Ingram. 1963. E.xtension 

of range of Asiatic clam to Cincinnati reach of the Ohio 

River. The Nautilus 77(1): 18-21. 
Mackie, G. L., and D. G. Huggins. 1976. Biological notes on 

Eupera eubensis (Bivalvia: Sphaeriidae) from Kansas. ./. 

Fish. Res. Board Can. 33: 1652-1656. 
Mackie, G. L., and S. U. Qadri. 1974. Calyculism in Musculium 

seairis (Pelecypoda: Sphaeriidae) and its significance. Can. 

J. Zool. 52: 977-980. 
Mackie, G. L., S. U. Qadri, and A. H. Clarke, 1974a. Byssus 

structure of larval forms of the fingernail clam, Musculium 

securis (Prime). Gin. J. Zool. 52: 945-946. 



1974b. Development of brood s;ics in Musculium 

securis Bivalvia: Sphaeriidae. The Nautilus 88(4): 109-111. 
. 1976a. Intra.specific variations in growth, birth pe- 



riods, and longevity of Muscuiium securis (Bivalvia: Sphaeri- 
idae) near Ottawa. Canada, Mulonihuiio 15(2): 4liV446. 
. 1976b. Reproductive habits of four populations of 



Musculium securis (Bivalvia: Sphaeriidae) near Ottawa, 
Canada. The Nautilus 90(2): 76-86. 

Monk, G. R. 1928. The anatomy and life history of a 
freshwater mollusk of the genus Sphaerium. J. Morph. 45: 
473-503. 

Rodgers, J. H., Jr., D. S. Cherry, J. R. Clark, K. L. Dickson, 
and J. Cairns, Jr. 1977. The invasion of Asiatic clam, Cor- 
bicula manilensis in the New River. Virginia. The Nautilus 
91(2): 43-46 

Sickel, J. B. 1973. A new record of Corbiada manilensis 
(Philippi) in the Southern Atlantic Slope region of Georgia. 
The Nautilus 87 {iy.n-\2. 

. 1976. An ecological study of the Asiatic clam, 

Corbicula manilensis (Philippi, 1841) in the Altamaha 
River, Georgia, with emphasis on population dynamics, pro- 
ductivity, and control methods. As abstracted in Corbicula 
Newsletter, ed. J. S. Mattice, Oak Ridge National 
Laboratory, Vol. 2(1), 1977. 

Sinclair, R. M. 1964. Clam pests in Tennessee water supplies. 
Jmir A WWA 56(5): 592-.599. 

. 1971. Annotated bibliography on the exotic 

bivalve Corbiada in North America, 1900-1971. Sterkiana 
43: 11-18. 

Sinclair, R. M. and W. M. Ingram. 1961. A new record for the 
Asiatic clam in the United States, the Tennessee River. The 
Nautilus 7i{3):lU-nS. 

Sinclair, R. M. and B. G. Isom. 1963. Further studies on the 
introduced Asiatic clam (Corbiada) in Tennessee. Tennessee 
Department of Public Health. 75 pp. 

Sterki, Victor. 1909. Some observations and notes on 
Musmdium. The Nautilus ^(2): 17-19. 

Thomas, G. J. 1959. Self-fertilization and production of young 
in a sphaeriid clam. The Nautilus 72(4): 131-140. 

. 1963 Study of a population of sphaeriid clams in 

a temporary pond. The Nautilus 77(2): 37-43. 

. 1965. Growth in one species of sphaeriid clam. 



The Nautilus 79(2): 41 -5i. 

Tilly, L. J. 1976. Persmal communication: Research super- 
visor. Savannah River Plant, Aiken, South Carolina. 

Yonge, C. M. 1962. On the primitive significance of the byssus 
in the Bivalvia and its effects in evolution. J. mar. biol. 
Ass. r. A'. 42: 113-12.5. 



Recent 

Akibumi Teramachi, an amateur conchologist, 
artist, and well-known Japanese shell collector 
died in Kyoto, Japan, at the age of 80, on 
December 6, 1978. At the age of 24 he developed 
tuberculosis and went to Wakayama Prefecture 
for his health. There he became an avid shell col- 
lector, and published his first two papers on con- 
chology in the Venvs. vol. 2, in 1930. Two genera. 



Death 

Temmachia and Akibumia, and several species of 
moUusks were named after him, especially by 
Kuroda and Habe. Cypraea katsuae was named 
after his wife. Some of the types in his collection 
were sold from time to time, and the holotype, 
for instance, of Teramaehia tibiaeformis Kuroda, 
is now in the Academy of Natural Sciences of 
Philadelphia. 



84 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



REDISCOVERY OF A PRESUMED EXTINCT RIVER MUSSEL, 
DYSNOMIA SULCATA (UNIONIDAE) 

Billy G. Isom', Charles Gooch', and Sally D. Dennis^ 



Several commercial mussel boats were sighted 
on the Cumberland River in July 1976. A visit 
was made to the area on September 1, 1976, to 
determine the species of mussels being taken 
commercially. Among the species found were 
several specimens of one that had been presumed 
extinct (Stansbery. 1970) or reduced to a single 
river system (Stansbery, 1971). The species was 
later taken live near Cumberland River at mile 
296.8, the same general area in which the mussel 
boats had been working. This species is believed 
to be confined to this portion of the Cumberland 
River in Tennessee. 

Lea (1829) described the species as "Shell sub- 
elliptical, inequilateral, ventricose, slightly 
marginate; valves thick; beaks nearly terminal; 
cardinal and lateral teeth large, and double in 
both valves; nacre purple." The type locality was 
listed by Lea as Ohio in his plate 8, fig. 12. 

Dysnomia sulcata (Lea, 1829) was reported to 
exist in the Cumberland River by Wilson and 
Clark (1914), who commented on its distribution: 
"Although this species seems to be pretty well 
distributed along a considerable stretch of river, 
we obtained only occasional examples here and 
there along the shore ... It can probably be pro- 
cured in large numbers during low water." 

"It is common enough to be pretty well known 
to the clammers, who call it 'peewee' on account 
of its small size, or 'cat's-claw' because of the 
peculiar clawlike structure on the marsupial ex- 
pansion of the female." 

Ortmann (1925) provided good locality records 
for I). !iiilrata. However, he considered the species 
an "immigrant" in both the Cumberland and 
Tennessee Rivers, its principal distribution 
centered clearly in the Ohio and Wabash Rivers. 

Neal and Allen (19(yl) reported finding only 
one sf)ecimen during their study of the mussels of 



'Tenne&see Valley Authority. E&D Building, Muscle Shoals, 
Alabama .^Sfifin 

'Tennessee Valley .Authority, F(jrestry Building, Norris, Ten- 
nessee 37828 



the upper Cumberland River. This specimen was 
found at Neeleys Ford near Burkesville, Ken- 
tucky. 

Stansbery (1970) stated that "Tlie big river D. 
a. mlcata form having a purple nacre may be ex- 
tinct, but the white-nacred D. .s. perobliquioi is 
still occasionally found in streams tributary to 
western Lake Erie or Lake St. Clair." However, 
Stansbery (1971) stated that D. f^ulcata was 
reduced to a single river system, the Green River 
in Kentucky'. 

Lack of recent locality records for this species 
may result from limited amount of collecting be- 
ing done in big rivers, especially the Cumberland 
River. The last comprehensive study of the mid- 
dle and lower Cumberland River was by Wilson 
and Clark (1914). 

We wish to thank Steven A. Ahlstedt for his 
assi-stance in this project. 



REFERENCES 
LITERATURE CITED 

Lea. Isaac, 1829 (18:5)). Observation on thie genus L'nio 
together with descriptions of eighteen species; and of the 
genus Sifiiiplnfiiotfi. now separated from the family of 
Naiades, containing nine species. Tmm. Ainer. Pliilim. Six: 
3:4.30-«l,pl.8.fig.l2. 

Neel, .Joe K. and William R. .Allen. 1964. The mussel fauna of 
the upper Cumberland Basin before its impoundment. 
il/a/nfo/oyfVil (.3): 427-459. 

Ortmann, A. E. 1925. The Naiad fauna of the Tennessee River 
below Walden Gorge. /I »ienV«« Midi Nat. 9(7): :321-372. 

Stansben,', David H. 1970. Eastern Freshw^ater Mollusks (I) 
The Mississippi and St. Lawrence River Systems. In: Pni- 
cfciliiiyy (if the Amrr. Malaaihiyicnl l'iu<i>i Si/niixisiiini on 
Rare ami F.ndangered Mollush. Ed. by A. H. Clarke, (1968): 
p. 19. 

. 1971. Rare and endangered freshwater mollusks 

in Eastern L'nited States. In: Hare and Endangered 
Mollusks (Naiads) of the U.S. Edited by Jorgensen and 
Sharp. Issued by the U.S. Dept of Interior. Region 3: pp. 
.5-18andl8e. 

Wilson. Charles B. and H. Walton Clark. 1914. The Musi^els of 
the Cumberliuid River and its Tributaries. Reixirt, W. S. 
Fish, Conim., Washington. D.C., No. 781. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 85 



A REVIEW OF THE SYSTEMATICS OF CYLICHNELLA GABB 
(OPISTHOBRANCHIA: SCAPHANDRIDAE) 

Terrence M. Gosliner 

Department of Zoolog>' 

University of New Hampshire 

Durham, N. H. 03824 

ABSTRACT 

.4 nin)-i)fi<>l<igirnl fttiidy ivm^ made oftii.r sperip^ of the geniif; Cylichnella Gahb. 1873. 
Cylichnella oryza wan studied anatornieaUyfor the first time. Coniparison of the in- 
fomiatum obtained in this study with that in the literature suggests that Utriculastra 
Thiele, 1925, should he regarded as a junior synonym o/ Cylichnella. C. canaliculata 
and C. inculta, while similar inform, are distinct species. C. cerealis is nuiintained as 
a valid species while C. eximia is suppressed as a junior synonym ofC. culcitella. 



INTRODUCTION 

The recent works of Marcus (1974, 1977), Rud- 
man (1971, 1973), Bouchet (1975) have dealt ex- 
tensively with the comparative morphology of 
members of the Cephalaspidea. Many species 
possess shells which are similar in form yet have 
dramatically divergent internal morphology. The 
systematics of the Cephalaspidea has been more 
clearly defined as a result of these studies. 

Two genera of the Scaphandridae, Cylichnella 
Gabb, 1873 and Utriculastra Thiele, 1925, have dif- 
ferent shell types. Cylichnella has an involuted 
spire while Utriculastra possesses a projecting apex 
of varying prominence (Marcus, 1958; Marcus, 
1977). Marcus (1977) noted that the gizzard and 
radula of members of both genera are virtually 
identical but differentiated the genera on the basis 
of several other criteria. Marcus (1977) described 
two subgenera, U. (Utriculastra) and U. (Tor- 
mtstra). My preliminary examinations suggest that 
a more detailed analysis of the status of Cylichnella 
and Utriculastra is warranted. The work of Marcus 
(1977) supplied an excellent analysis of 
Utriculastra and its component subgenera and 
species and provides the basis of comparison for the 
work presented in this paper. 

I would like to thank Dr. Ruth Turner of Har- 
vard University for her encouragement and for her 
critical comments, Dr. Eveline Marcus of the 
University of Sao Paulo, Brazil for her suggestions 
and enthusiasm, Dr. M. Patricia Morse of North- 
eastern University, Mr. Kee Muschenheim of Yale 
University and Mr. Gale Sphon of the Los Angeles 



County Museum for providing specimens. I would 
particularly like to thank Dr. Larry Harris of the 
University of the New Hampshire for his guidance 
and friendship and for his help in collecting 
specimens in Nova Scotia. 

MATERIALS AND METHODS 
Three specimens of Cylichnella cerealis (Gould, 
1852) were collected from Bodega Harbor, Bodega 
Bay, California (lat. 38°18'N.; long. 123°03' W.) on 
June 17, 1976. Numerous specimens of C. inculta 
(Gould, 1856) were collected from Morro Bay, 
California (lat. 35°20' N.; long. 120°50' W.) on July 
17, 1976. C. canaliculata (Say, 1826) was collected 
on August 17, 19, 26, 1977 from several localities in 
Nova Scotia and New Brunswick, and on Sep- 
tember 3, 1977 from Pt. Judith, Rhode Island (lat. 
4r24' N.; long. 72°30' W.) Additional specimens of 
C. canalicxdata from Long Island Sound were 
provided by Mr. Kee Muschenheim. Several 
specimens of C culcitella (Gould, 1852) from San 
Miguel Island, California, (lat. 35°59' N.; 120°25' 
W.) were loaned by the Los Angeles County 
Museum. Three specimens of C. bidentata (Orbigny, 
1841) from the Eveline Marcus collection were 
made available by the Department of Mollusks, 
Museum of Comparative Zoology, Harvard Univer- 
sity. Numerous specimens of C. oryza (Totten, 
1835), dredged from Long Island Sound, were 
provided by Mr. Kee Muschenheim. 

Specimens were observed alive whenever 
possible and were dissected for morphological com- 
parison. Several (circa 5-10) individuals of each 



86 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



species were dissected to determine intra as well as 
interspecific variation. The anatomy of the shell, 
postero-lateral e.xtension of the mantle, radula. 
jaw, gizzard plates, nervous system and reproduc- 
tive system was studied for each species. 

Cylichnella Gabb, 1873 

type species: Bulla bidentata Orbigny , 1841 
1. C. ranaliculata (Say. 1826) 

Specimens collected from three different 
localities in New Brunswick and Nova Scotia 
exhibited different shell characteristics. Specimens 
fi-om Parlee Beach. Shediac, N. B. (lat. 46° 12' N.; 
long. 64°30' W.) an open sandy beach on the Nor- 
thumberland Strait, have a spire which is elongate 
and clean; those from Pictou Harbor, N. S., (lat. 
45°40' N.; long. 62° 45' W.) a quiet area of mixed 
fine sand and mud have an elongate spire which is 
covered with sand and mud; and the spires of all 
specimens (100) from Bras d'Or Lake, N. S., (lat. 
46°05' N.; long. 60° 48' W.) a large calm estuary, are 
almost completely eroded. The shell ranges from 3..5 
to 6.0 mm in length. In all cases the periostracum is 
thin and transparent. The postero-lateral elabora- 
tion of the mantle edge is .short. 

The radular formula in five specimens ranges 
from 12-1.") X 1. 1. 1. Tlie jaws are cuticular and 
possess platelets as depicted by Marcus (1977). The 
gizzard plates of C. canaliculata are similar to that 
described by Marcus (1977) with a wide heart 
shaped dorsal plate and two narrow sub-equal 
latero-ventral plates. In six specimens observed the 
large gizzard plates ranged in length from .85 to 1.0 
mm while the lateral plates ranged from .95 to 1.25 
mm in length. 

The nervous system (Fig. 1) consists of two large 
cerebral and two large pedal ganglia. The cerebral 
and pedal commissures are approximately equal in 
length. The left and right pleural ganglia are small 
and connect to the cerebal and pedal ganglia. Im- 
mediately posterior to the right pleural ganglion 
lies the right parietal ganglion. From there the 
right visceral nerve runs posteriorly to the suprain- 
testinal ganglion which is situated at the level of 
the mid-portion of the gizzard. At the dorsal .sur- 
face of the ganglion the short osphradial nerve con- 
nects with the vestigial osphradium. Near its 
posterior limit the right visceral nerve crosses the 



left visceral nerve dorsally and loops anteriorly to 
the small genital ganglion. From the genital 
ganglion emanates the genital nerve and the left 
visceral nerve. After a moderate distance the left 
visceral ner\'e gives rise to the closely as.sociated 
visceral and sub-intestinal ganglia. Midway be- 
tween the left pleural ganglion and the sub-intes- 
tinal ganglion the left visceral nerve gives rise to 
the pallial nerve. At this juncture the visceral 
nerve is slightly thickened yet does not form a 
distinct pallial ganglion. 

The reproductive system of C. canaliculata (Fig. 
2) consists of a series of diffuse lobes of the ovotestis 
which are interdigitated with the digestive gland. 
The narrow pre-ampuUary duct is short and widens 
intf) an ampulla consisting of numerous con- 
volutions. The ampulla narrows into an elongate 
and relatively straight post-ampullary duct. A 
semiserial receptaculum seminis (terminology 
following Edmunds. 1970) enters the post- 
ampullary duct which continues distally to the 
common genital atrium. Also entering the com- 
mon atrium are the large female accessory organs, 
the albumen and mucus glands. The duct of the 
spherical bursa copulatrix also enters the common 
atrium at this point. From the gonopore an open 
seminal groove runs anteriorly to the protrusible 
cephalic penis. 

2. C. inculta (Gould, 1856) 

The shell of C. inculta has an elevated spire. The 
protoconch may be present or eroded. The 
periostracum is transparent. In the forty specimens 
studied the shell is 3.5 to 6.0 mm long. The postero- 
lateral margin of the mantle is produced into a 
short extension. The radular formula in four 
specimens varies from 18-20 X 1.1.1. The jaws are 
thin and cuticular and possess platelets as depicted 
by Marcus (1977). The gizzard is similar to that 
described by Marcus (1977). The dorsal plate is 
broad and heart shaped and ranges from .80-1.05 
mm in length. The narrow paired gizzard plates are 
.9.5 to 1.10mm in length. 

The central nervous system and reproductive 
system are indistinguishable from those of C. 
canaliculata with the exception of the penis. In C. 
inculta the prostate is thick and elongate while in 
C. canaliculata it is much thinner and shorter. 



Vol. 98 (2-3) 



April 23, 1979 



THE NAUTILUS 87 







FIGS. 1-4. Cylichnella canaliculata (Saij). 1, central nervous 
syxtem (scale 1.0 mm). 2, reproductive system (scale 0.5 mm). 
3, Cylichnella culcitella fGoiiUI) (xralr 1.0). 3a, receptafuliim 



Legend to Lettering 



a-ampulla 
ag-albumen gland 
bc-bursa copulatrix 
c-eerebral ganglia 
g-genital ganglion 
ga-genital aperture 
me-membrane gland 
mg-mucus gland 
ot-ovotestis 



p-penis 

pa-parietal ganglion 
pl-pleural ganglion 
pr- prostate 

rs-receptaeulum seminis 
sb-subintestinal ganglion 
sp-supraintestinal ganglion 
v-visceral ganglion 



seminis. 3b, entire reproductive system. 4, Cylichnella biden- 
tata (Orhigny) (scale 0.2 mm), reproductive system. 

3. C. culcitella (Gould, 1852) 

The shell is 9.5 to 15.0 mm in length in the 20 
specimens observed. The spire is slightly to 
moderately elevated. The periostracum is trans- 
parent-browTi with numerous spiral striations. 
The length of the po.stero-lateral mantle e.xtension 
varies from moderate to extremely long. It recurves 
to the right side of the animal and extends ven- 
trally to the ventral surface of the body whorl. 



88 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



In C. culcitella there are 23, 24 and 28 pairs of 
lateral teeth in three individuals observed. In the 
specimen with 24 pairs of lateral teeth there is a 
row of 14 small, rectangular rachidian teeth, while 
rachidians are entirely absent in the other two in- 
dividuals from the same collection. There are 55 to 
66 denticles along the entire margin of the lateral 
teeth. The jaws consist of a thin membranous 
cuticle without platelets. In four specimens ob- 
served the small unequal gizzard plate is laterally 
flattened and is 1.6 to 2.9 mm long. The large sub- 
equal gizzard plates are 2.4 to 4.9 mm long. 

The reproductive system of C. culcitella is 
similar to that of C. canaliculata except that the 
receptaculum seminis is serial in one specimen 
(Fig. 3b) and semi-serial in two other specimens 
(Fig. 'ia). The penis and prostate in three specimens 
observed is similar to that described by Marcus 
(1977) and ranges from 7 to 13 mm in length. 

4. C. cerealis (Gould, 1852) 

The shell is 6.5 to 11.0 mm in length and has a 
moderately elevated spire. The periostracum is 
transparent with brown spiral striations of varying 
prominence. The postero-lateral extension of the 
mantle is elongate and recurves to the left along 
the dorsal surface of the body whorl. 

The radula in the three specimens observed con- 
sists of 17, 19 and 21 pairs of lateral teeth. In no 
case is there any trace of rachidian teeth. The jaws 
are thin and membranous without platelets. In the 
four specimens observed the small, uneven gizzard 
plate is dorso-ventrally flattened and 1.0 to 1.5 mm 
long. The large subequal plates are 1.5 to 2.5 mm 
long. 

The nervous system is identical to that described 
for C. canaliculata. 

The reproductive system is the same as in C. 
canaliculata except that the receptaculum seminis 
in one specimen is serial and semi -serial in 
another, as in C. culcitella. In the three specimens 
studied the penis consists of an elongate, thickened 
prostate and a conical papilla which lacks 
papulations. The penis ranges from 8 to 12 mm in 
length. 

5. Cylichnella bidentata (Orbigny, 1841) 

The shell is elongate and cylindrical with a 
bulloid apex. In the three specimens studied the 
shell is 2.8 to 3.1 mm long and 1.4 to 1.6 mm wide. 
The periostracum is thin and transparent without 



striations. The postero-lateral extension of the 
mantle is of a moderate length. 

The radular formula in two specimens dissected 
consists of 14 and 15 X 1.1.1. The jaws are 
thickened at the anterior edge but lack any 
platelets. The gizzard consists of a wide heart 
shaped dorsal plate which in two individuals 
ranges from .55 to 1.0 mm in length. The narrow 
paired plates range from 0.6 to 1.0 mm in length. 

The nervous system and the reproductive system 
(Fig. 4) are not significantly different from that of 
Cylichnella canaliculata. The penis is identical to 
that described by Marcus (1958). 
6. C: oryza (Totten, 1835) 

The shell (Fig. 5) is orbicular with a depressed 
bulloid apex. The preserved animals vary in length 
from 1.4 to 2.8 mm and 0.7 to 2.0 mm in width. The 
postero-lateral extension of the mantle is ex- 
tremely short. 

In the two specimens examined the radula (Fig. 
6) has a formula of 16-17 X 1.1.1. There are 10 to 16 
denticles on the inner margin of the laterals. The 
jaws consist of a thin chitinous cuticle which lacks 
platelets. The gizzard (Fig. 7) consists of a large 
heart shaped dorsal plate and two smaller, 
subequal ventro-lateral plates. The dorsal plate in 
the one specimen examined is 1.35 mm long and .97 
mm wide. The two subequal plates are 1.25 mm and 
1.22 mm in length and .51 mm and .50 mm wide, 
respectively. 

The central nervous system (Fig. 8) appears to be 
entirely euthyneurous as the right visceral nerve 
does not cross the left visceral nerve. The relation- 
ships of the ganglia are similar to those of C. 
canaliculata except that the visceral nerves are 
shortened. 

The reproductive system of C. oryza (Fig. 9, 10) 
closely resembles that of C. canaliculata. The only 
difference is that the receptaculum seminis is 
spherical with an elongate duct in both specimens 
dissected. The penis consists of a wide prostate 
which narrows anteriorly for most of its length. 
The penial papilla is broad without any armature 
or papillae. 

DISCUSSION 

The morphological similarities between the 
species described is striking. Marcus (1977, p. 17) 
noted that the radular teeth and gizzard plates of 
Cylichnella canaliculata (as Utriculastra) and 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 89 










FIGS. 5-10, Cylichnella oryza (Totten). 5, shell (scale 0.3 mm). 
6, radular teeth (scale 10 mj/ / 7, gizzard plates (scale 0.5 



mm). 8, central nervous system (scale 0.3). 9, penis and pro- 
state (scale 0.1 mm). 10, reproductive system (scale 0.25 mm). 



90 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



Cylichnella hidentata were identical yet stated 
that "the depressed apex (of the shell), the shape of 
the head shield, posterior adherence and the male 
organ are different in both forms and justify 
generic separation." A detailed examination of 
these differences is required. 

The presence of a bulloid shell in Cylichnella ver- 
sus an elevated spire in Utriculastra appears to be 
a useful character for generic separation. However, 
if one examines the shells of species which Marcus 
considered as members of Utriculastra one en- 
counters a wide range of form. C. rolleri (Marcus, 
1977) generally h;i.s an e.xtremely elongate spire 
(unpublished data) while in C. eximia the spire is 
scarcely elevated (Marcus, 1977). Most other species 
are somewhat intermediate between these two in 
spire elevation. 

The shape of the head shield in C. carmliculata, 
when fully extended, is rectangular and more 
elongate than shown by Marcus (1977, Fig. 23). The 
posterior lobes of the head shield are rounded in C. 
canaliculata whereas they are acutely pointed in C. 
hidentata. The lobes of C. rolleri. however, are 
elongate and acute as in C. hidentata. I am unable 
to discern any consistent difference in the shape of 
the head shield between species considered as 
Cylichnella and Utrifulmtrn by Marcus (1977). 

It appears to me that the "posterior adherence" 
(Marcus, 1958) of Cylichnella bidentatn is 
homologous with the "cloacal tentacle" (Marcus, 
1977) found in C. cerealis, C. culcitella and Tor- 
natina conspicua. I prefer the term posterior ex- 
tension of the mantle. Cylichnella oryza lacks any 
noticeable extension of the mantle while in C. in- 
cut ta and C. canaliculata it is extremely short. In 
specimens of C. cerealis from Bodega Harbor the 
extension was as highly elaborated as in Tomatina 
conspicua. The length of the extension varies in 
specimens of C culcitella from San Miguel Island. 
There seems to be no consistent difference between 
Cylichnella and Utriculastra with respect to this 
character. 

The final character on which Marcus (1977) 
based her separation of Cylichnella and 
Utriculastra was the structure of the penis. The 
papilla of C. hidentata bears a row of papillae along 
its margin (Marcus, 1958, present study). In C. 
culcitella the penis contains similar papulations 
(Marcus, 1977). The penis of C. inculta, C. 



rnnnlinilntn and C aryza lacks any papulations. 
Marcus (1974) has shown that some species of 
Scaphander posses papulations on the penial 
papilla while others lack them entirely. Simi- 
larly, Rudman (1974) has shown that Aglnja 
ocelligera has a penial papilla with numerous 
papulations while other members of the genus 
have a naked penis. There seems to be little basis 
for separation of Cylichnella and Utriculastra 
with regard to the penis. 

The nervous systems of all species of Cylich- 
nella in this study were virtually identical with 
the exception of C. oryza which is completely 
euthyneurous yet has the same configuration of 
ganglia. Though all other species observed in this 
study, including C hidentata differ slightly from 
C (rryza their differences are not regarded as 
having taxonomic importance. 

In the examination of the reproductive systems 
of the six species observed in this study the most 
substantial difference occurred within the species, 
C culcitella and C cerealis. In both species the 
receptaculum seminis may be either serial or semi- 
serial. Since the greatest difference observed is of 
an intraspecific nature there is no basis for 
separating genera. 

When the observed species of Cylichnella are 
compared there is no characteristic which clearly 
differentiates them at the supraspecific level. The 
differences in the radula and gizzard of Marcus' 
two subgenera Utriculastra. U (Utriculastra) and 
['. (Tonuistra). are more substantial than those 
between U. (Utriculastra) and Cylichnella. I 
feel that the taxa Cylichnella and Utricula.'^tm 
form a natural, monophyletic genus and should 
be regarded as Cylinchnella Gabb. 1873, on the 
basis of priority. Utriculastra is regarded as the 
junior synonym. 

Marcus (1977) described two subgenera of 
Utriculastra, U. (Utriculastra) and U. (Tomastra). 
U (Utriculastra) is characterized by having a 
deltoid unpaired gizzard plate while ['. (Tor- 
nastra) has a round unpaired plate. However, the 
vast majority of morphological characteristics (e.g. 
shell, radula, nervous and reproductive systems) 
are virtually identical between species placed in 
both subgenera. In Philine, the monotypic genus of 
the closely allied Philinidae, the shape of the giz- 
zard plates varies considerably or may be absent 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 91 



but no subgeneric separation is made. I feel that 
the separation of Cylichnella is not useful as it ap- 
pears to form a natural generic taxon. I therefore 
also supress Tomastra as a junior synon>Tn of 
Ci//(W;«e//aGabb, 1872. 

The large number of synonyms of Cylichnella 
canaiieulata attests to the taxonomic confusion 
regarding this species. Wells and Wells (1962) 
examined numerous specimens of Cylichnella from 
North Carolina. They maintained that two species 
were present, Retttsa canaiieulata and Acteocina 
candei. Although closely allied, the species were 
placed in separate genera, as the absence of a 
radula in Retusa ohtusa. the type species oi Rctusa. 
had not been verified. Subsequent study has con- 
firmed that a radula is wanting in Retusa ohtusa 
(personal observation) and that it is inappro- 
priate to place C. canaiieulata in Retusa. Wells and 
Wells regarded the two species as being distinct on 
the following bases: slight conchological dif- 
ferences, the presence of more numerous denticles 
on the rachidian and lateral teeth of the radula in 
C candei and an offehore distribution of C. candei 
vidth an estuarine, inshore distribution in C. 
canaiieulata. Wells and Wells described an entirely 
contained developmental pattern for C. 
canaiieulata. Franz (1971) examined the develop- 
mental biologv' of C. canaiieulata from Connecticut 
and determined that the species e.xhibits a 
plankotrophic pattern. He offered several possible 
explanations for this discrepancy. My observations 
of an estuarine population in Pictou Harbor, Nova 
Scotia, confirm that the species has planktotrophic 
development. Marcus (1977) discussed the criteria 
used to separate the two species and suggested that 
intermediates in conchological and radular mor- 
phology are common. She also noted that these 
characteristics cannot be correlated with estuarine 
or offshore distribution and that C. candei should 
be regarded as a junior synonym of C. canaiieulata. 
My observations of C. canaiieulata are entirely sup- 
portive of Marcus' findings. 

Cylichnella canaiieulata is morphologically very 
similar to C. inculta. C. canaiieulata has 12 to 15 
rows of radular teeth while C. inculta has 17 to 20 
rows. The large dorsal gizzard plate of C. incidta is 
broader than in C. canaiieulata and also contains a 
proportionately larger thickened central portion. 
The penis of C. iiiculta contains a thicker and 



longer prostate than that of C. canaiieulata. While 
these differences are minor they do appear to be 
consistent and warrant specific separation. 

Marcus (1977) stated that C. cereali's was distinct 
from C. eximia and C. culcitella. The material from 
Bodega Harbor supports this contention. The un- 
paired gizzard plate is dorso-ventrally flattened 
rather than laterally compressed. The lateral teeth 
in C. cerealis possess 20 to 37 denticles compared to 
40 reported for C. eximia and 55 to 66 for C. 
culcitella. Ball's (1922) contention that C. cerealis 
are young C. culcitella is refuted since all 
specimens collected at Bodega Harbor were 
sexually mature and were collected with egg 
masses. 

The separation of C. eximia and C. culcitella 
seems more difficult. Marcus (1977) stated that 
they were distinguished by their radular teeth, 
penis and gizzard, yet described the radula of C. 
culcitella as corresponding "to that of eximia". The 
gizzard plates depicted for C. culcitella are slightly 
more oval than those of C. eximia (Marcus, 1977, 
figs. 57, 68, 69, 70, 74) yet specimens from San 
Miguel Island showed similar variation. The penis 
and prostate was 20 mm long in C. eximia and 3 
mm long in C. culcitella in specimens of approx- 
imately equal length. Specimens studied in this 
paper had penis and prostate lengths of 7. 9 and 13 
mm. Due to the intermediate length of the penis 
along with similar morphology of the other systems 
the two species are here considered as s>Tion>TTious 
with C. culcitella (Gould, 1852) having priority. 

Based on the anatomical work I have undertaken 
I propose the following taxonomic arrangement: 

Genus Cylichnella Gabb, 1873 

Cylichtiella Gabb. 187:3: 273. {i\-pe siiecies: Biilln hidoitnta Or- 

bigny, 18-11) 
Utriailastra Thiele, 1925: 235. (type species; Volnaria 

canaiieulata Say, 1826) 
Tamastra Marcus, 1977: 5. (tjTJe species: Bulla eximia Baird. 

18&3) 

Cylichnella biden lata (Orbigny, 1841) 

Bulla bidentata Orbigny, 1841. 

Cylichnella bidentata (Orbigny, 1841) Gabb, 1873. 

Cylichnella canaiieulata (Say, 1826) 

Viiharia canaiieulata Say, 1826. 
Bulla candei Orbigny, 1841. 



92 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



Utriatlus cavdiculatus (Say. 1826) Watson. 1886. 
Tormtina cmdiculata (Say. 1826) Pilsbry. 1895. 
Tormtim candei (Orbigny. 1841) Pilsbry. 189,5. 
Retusa (i'triadastmjcanalicutata (Say. 1826)Thiele. 1925. 
Artaeociyia candei (Orbigny. 1841) Carcelles. 1944. 
Acteodna canaliculata (Say, 1826) Perrv' and Schwengel. 19.55. 
Retusa candei (Orbigny, 1841) Abbott, 19,58. 
Acteodna candei (Orbigny, 1841) Wells and Wells. 1962. 
Utriailoftra (i'triculastm) canalicidata (Say, 1826) Marcus, 
1977. 

Cylichnella inculta (Gould, 18.56) 

Tomatina inculta Gould, 18.56. 

Utricidaatra H'trindastm) inculta (Gould. 18.56) Marcus. 1977. 

Cylichnella cerealis (Gould, 1852) 

Bulla cerealis Gould, 18.52 

Utriadastm (Tornastral cerealis (Gould. 18.52) Marcus. 1977. 

Cylichnella culcitella (Gould, 1852) 

Bulla ndcitetta Gould. ia52 

Btdlina eximia Baird, 186.3. 

Utricidaatra (Tomastra) culcitella (Gould, 1&52) Marcus, 1977. 

Utricidaatra (Ti'mastra) erimia (Baird. 18S3) Marcus. 1977. 

Cylichnella oryza (Totten, 1835) 

Bulla (rryzaTottenASS^. 

Cylichnella oryza (Totten, 1835) Marcus, 1958. 

Cylichnella knockeri (E. A. Smith, 1872) 

Tomatina knockeri Smith, 1872 

Utriculastra (Tormstra) knockeri (E. A. Smith. 1872) Marcus, 
1977. 

Cylichnella roUeri (Marcus, 1977) 

Utrindastra (Tornastral rolleri Marcus, 1977. 



Other species possibly belong in the genus 
Cylichnella (Marcus, 19.58: 8: Marcus. 1977:(i) but 
cannot be assigned with certainty until they have 
been studied morphologically. 



LITERATURE CITED 

Bouchet, Philippe. 1975. Opisthobranches de profondeur de I'o- 

cean Atlantique. I. Cephalaspidea. Cahiers de Biologie 

Marine 16: m-'i^o. 
Dall. William H. 1922 A note on Arteocina. The Nautilus 35: 96. 
Edmunds. Malcolm. 1970. Opisthobranchiate Mollusca from 

Tanzania. II. Ek)lidacea (Cuthonidae. Piseinotecidae and 

Facelinidae). I'nic. Malac. Sac. Limdim 39: 15-.57. 
Franz. David. 1971. Development and metamorphosis of the 

gastropod Acteocinn canalicidata (Say). Trans. Amer. Micros. 

Soc. 90(2): 174-182 
Gabb, William M. 1873. Description of some new genera of 

Mollusca. Proc. Acad. Nat Sci. Philadelphia 1872: 270-274. 
Marcus, Ernst. 1956. Notes on Opisthobranchia. Bol. Inst. 

Oceana. S. Pauh, 7(1958): 31-79. 
19.58. On western Atlantic opisthobranch 

gastropods. Amer. Mus. Novitates, no. 1906: 1-82. 
Marcus, Eveline duIBois-Reymond. 1974. On some Cephalaspidea 

(Gastropoda: Opisthobranchia) from the western and middle 

Atlantic. Bh//. Mar. Sci 14(2): 3(K)-371. 
1977. On the genus Tomatina and related forms. 

Jofurn. Moll Stiidicx (suppl.2): 1-.3.5. 
Rudman, W. B. 1971. On the opisthobranch genus Haminoea 

Turton and Kingston. Pacific Sci. 25: 549-.S59. 
1973. The genus Philine (Opisthobranchia, 

Gastropoda). Pnic. Malac. Snc. London 40(3): 171-187. 
. 1974. A comparison of Chflidoiiura. Navanax and 



Aylaja with other genera of the .^gtajidae (Opisthobranchia: 
Ga.stropoda). Ziiol. J. IJniiean Soc. London 54: 178-212. 

Thiele. .Johannes. 1925. Gastropoda der Deutschen Tiefsse- 
Expedition Pt. 2. Wi.ss. Eiyebnisse dcr Deutschen Tiefsee- 
Krpedition 17: .37-382. 

Wells, Harry and Mary .lane Wells. 1962. The distinction be- 
tween Acteodna candei and Retusa canaliculata. The 
Nautibis 75(3): 87-93. 



NEWS 



Malacological 
The main archives for the American Mala- 
cological Union have now been removed from the 
Delaware Museum of Natural History and placed 
in more convenient and accessible quarters in the 
Department of Malacology, Academy of Natural 
Sciences of Philadelphia, 19th and The Parkway, 
Philadelphia, PA 19103 (stewardship is in the 
hands of Dr. George M. Davis; phone 1-21,5- 
299-1132). 



Archives Moved 

The archives contain documents, correspond- 
ence, photographs and information on about 1.50() 
professional and amateur American malacolo- 
gists, and are available for e.xamination by 
serious students of historical malacology. New 
material, e.specially of historical value, is most 
welwme at the new center, and will be properly 
curated and preserved. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 93 



SHELL SPINULES OF THE BIVALVE LYONSIA HYALINA' 

Robert S. Prezant 

College of Marine Studies 
University of Delaware 
Lewes, Delaware 19958 

ABSTRACT 

Sihall. Clinical pnijcctiims of the periostmmm cover the outer shell surfaces (f 
the hirnlve Lyonsia hyalina Conrad. These radially arranged npimden help en- 
tangle a mucoid secretion produced hy niaidle glands and aid in the retention of 
sand grains u-hich adhere to the shell. Vie sand-corer helps stabilize the bivalve in 
the s^ibstriifuui and may lend some protection to ds thni shell. 



Many members of the bivalve family Lyonsi- 
idae have the curious habit of attaching sand 
grains to the outside of their shells. Of the three 
genera of this family, Lyonsia is typically found 
partially buried with at least some portion of its 
shell covered with adhering sediment. Entodesma. 
a rock-crevice nestler, and Mytilimeria, found 
embedded within compound tunicates, will attach 
some sediment to their shells if grown within a 
sand substratum (Yonge, 1952). The ability of 
Lyonsia to glue sand to its valves was previously 
attributed to a minutely fringed (Morris, 1973; 
Emerson and Jacobson, 1976) or sticky (Yonge, 
1952) periostracum. Prezant (1979) showed that 
small, multicellular glands which line the mantle 
edge of L. hyalina secrete a mucoid product over 
the periostracum, and it is this which is responsi- 
ble for adhesion of sand. 

The superfamily Pandoracea has many in- 
faunal genera, including Lyonsia, which are 
described as having "granular" shell surfaces. The 
granulations or spinulations increase shell sur- 
face area and help stabilize the bivalve within 
the substratum (Aller, 1974). The small spines of 
Lyonsia are often obscured by adhering sand, and 
are thus not exposed to the substratum to aid in 
stabilization. This investigation was thus de- 
signed to examine the role of these minute pro- 
jections relative to the attachment of sediment to 
the shell of L. hyalina. 



'University of Delaware, College of Marine Studies Contribu- 
tion No. 131. 



Methods 

Lyonsia hyalina were collected from Delaware 
Bay from a muddy-sand substratum at a depth of 
about 15 meters. Shells were gently cleared of 
most adhering sand grains with a fine camel's 
hair brush. Valves were carefully opened and the 
animal removed. Shells were then rinsed in 
distilled water, and some were dipped in 0.53% 
sodium hypochlorite (10% commercial Clorox) 
and some in 20% 1 N hydrochloric acid for 30 
seconds, and again rinsed in distilled water. 
Valves were then dried for 48 hours in a 60°C 
oven. Dry shells were fractured, and fragments 
were mounted on scanning electron microscope 
stubs with silver paint, coated with gold, and ex- 
amined on a Cambridge scanning electron 
microscope. 

Results 

The nacreous shell of Lyonsia hyalina is thin 
and fragile but has a well developed periostracum 
with numerous periostracal striations which 
radiate from the umbones. A surface view at low- 
magnification of a partially cleaned shell (Fig. 1) 
reveals the prominent striations and minute 
spines which run parallel to the radial sculptur- 
ing. There are 7 to 8 columns of these spinules 
between each pair of periostracal striations. 
Mucus, secreted by mantle glands (Prezant, 1979), 
forms a tight web along the radial striations (Fig. 
2) and is further entangled by the small spines. 

The exceedingly small spinules are truncated at 
their tips (Figs. 3 and 4), and average 5.5 ycm in 
height and 7.5 \xm in width at their base in a 



94 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



bivalve 14 mm limK. The base of each spinule is 
sunken into a slight depression of the underlying 
supporting shell (Fig. 3). The spinules, which are 
highly regimented in distribution (Fig. 5), aver- 
age a distance of 15 i/m from one to another in 
either direction. In the Cloroxed specimen (Fig. 
6), the spinules have been partially dissolved, 
especially peripherally suggesting an organic 
component. The surface of the periostracum in 
the treated specimen appears pitted (Fig. 6). 
Treatment in dilute hydrochloric acid further 
reduces the spinules, suggesting a calcareous por- 
tion. The latter occurs primarily in the central 
region of the spinule. This may indicate that the 
spinule is composed principally of an aragonitic 
core surrounded by periostracum. 

Adhesion of foreign particles to the shell is 
aided by the large number of truncated spinules 
which help entangle the mucoid secretion 
generated by the mantle glands. The viscous 
mucus is laid down above, but in conjunction 
with, the periostracum. 

Discussion 

Unlike the spinules of Laternula flexuosa, 
another member of the Pandoracea, those of Li/on- 
siu are not "prefabricated" in the mantle (Aller, 
1974), but are laid down along with the rather 
thin periostracum. This being the case, the spi- 
nules are calcified periostracal components as 
defined recently by Carter (1978). Allen and 
Turner (1974) discussed several Verticordiids 
possessing mantle glands, which attach sediment 
to their shells, and have calcareous spinules 
which may be preformed. Aller (1974) considered 
attachment of external particles to the shell a 
supplementation, using "prefabricated" ex- 
traneous components in place of naturally 
"prefabricated" spines. The latter author viewed 
such supplementation, whether foreign or 



natural, as a consistent theme within the Pan- 
doracea. 

The external adhesive properties of valves of 
most Lyonsiids produces greater surface re- 
sistance through attachment of sand grains, and 
thereby greater stability within the substratum. 
TTie sand cover of Lyomna hyalinn. and most like- 
ly all other species of Lyonsia, may act secondari- 
ly as an armor protecting the thin shell, and sedi- 
ment adhering around the otherwise exposed si- 
phonal region may act as a defensive barrier or 
camouflage. 

ACKNOWLEDGMENTS 

I wish to thank Dr. M. R. Carriker for reading 
the manuscript, G. T. Entrot for help with the 
scanning electron microscope and P. Savage for 
tj-ping the manuscript. 

LITERATURE CITED 

Allen, J. A. and J. F. Turner. 1974. On the functional mor- 
phology of the family Verticordiidae (Bivalvia) with 
descriptions of new species from the abyssal Atlantic. Phil. 
Trans. R,ni. Sm:: London R 268: 401-.5.%. 

Aller, R. C. 1974. Prefabrication of shell ornamentation in the 
bivalve Laternula. Lethaia 7: 43-56. 

Carter, J. G. 1978. Ecology and Evolution of the 
Gastrochaenacea (Mollusca; BivalVia) with Notes of the 
Evolution of the Endolithic Habitat. B>dl. Peabody Mux. 
Nat.Hkt.il: 1-92. 67 figs. 

Emerson. B. and M. K. Jacobson. 1976. American Museum of 
Natural History Guide to Shells. A. A. Knopf Inc., N.Y., 482 
pp. 

Morris. P. A. 1973. A Field Guide to Sheik of the Atlantic 
and Chdf Coasts and the West Indies. H. Mifflin Co., Boston, 
330 pp. 

Prezant, R. S. 1979. The structure and function of the radial 
mantle glands of Lyonsia hyalina (Bivalia: Anomal- 
odesmata). ./m/r Zool. London 187: In Press, 

Yonge, C. M. 1952. Structure and adaptation in Lntodeitma 
sarifola (Baird) and Mytilimpria nuttatlii Conrad - with a 
discussion on evolution within the family Lyonsiidae 
(P^ulamellibranchia). Univ. Cal. Pub. Zool. 55: 439-450. 



FIGS. 1-6. 1, Surface vieiv of a partially cleaned shell o/ Lyonsia hyalina. Several sand grains remain adhered to the mucoid 
coat which covers much of the periostracum. The prominent radial striations of the periostracum and the xmall spinules which 
run parallel to them are evident. 75X. 2, Magnified view of the strand4ike mucoid secretion which ftmns a webbed pattern 
along the radial striations of the periostracum. 6iOX. 3, A fi-actured section through the shell ofh. hyalina revealing the trun- 
cated nature of the /leriostmcal spinules. The underlying nacre and tnyostracum are also ei-ident. 760X. 4, Magnified view of a 
fractured spinule showing its confluence with the periosttrwum. .VCK)X. 5, An oblique surface view of the periostracum showing 
alignment of the spinules. KXlflX. 6, FolUnring treatment in sodium hypochlorite the xpinules were dissolved revealing their 
organic nature. This micrograph also shows the pitted outer surface of the shell after removal of the m ucoid coat. 1200X. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 95 




l-'^*s^. 




Sb^ |m^ :V i 




Explanation ov (iippimtr page (Shell Spinules of the Bivalve. Lyonsia hyalina) 



96 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



A BIOGRAPHY OF ANDREW GARRETT. EARLY NATURALIST OF POLYNESIA: PART 2* 
CATALOGUE OF MOLLUSCAN SPECIES AND BIBUOGRAPHY 



William J. Clench 

Honorary Curator of Malacology 
Museum of Comparative Zoology 
Cambridge, Massachusetts 02138 



The Andrew Garrett Shell Collection 

The Garrett collection of land and marine shells, 
together with Garrett's conchological library and a 
few manuscripts, but not his journal, were pur- 
chased by the Bishop Museum in Honolulu, Hawaii, 
some time prior to 1899. Exact data concerning this 
purchase are lacking. Apparently, the items were 
not in the museum in 1893, when the natural his- 
tory portion of the "Preliminary catalogue" was 
printed, for under marine shells only the Baldwin 
collection and some specimens from the Govern- 
ment Collection were mentioned, but they may 
have arrived a year or more before 1899, when the 
first mention of the collection is made in printed 
records of the museum. Dr. Wm. T. Brigham had 
had time to have the specimens mounted on paste- 
board blocks and labels printed before then. 

In the Spring of 1899, Dr. Wm. H. Dall, of the U. 
S. National Museum, was employed by the Museum 
Trustees, upon recommendation of the Director 
(Dr. Brigham) to come to the Bishop Museum and 
examine the collection. He arrived August 16, and 
spent two months making his study and correcting 
the nomenclature. His report is published in the 
Report of the Director for 1899 (Occasional Papers, 
1(2): 10-13). Dall estimated that the collection con- 
tained about 25,000 specimens, representing be- 
tween 8,000 and 9,000 species, about one-fourth of 
them land shells, all neatly mounted and with 
printed labels, and largely with localities, at least 
to island groups. 

Andrew Garrett's shell collection was one of the 
most romplete for Pacific areas of that period. It 
formed the basis for many early descriptions of 
species, and contains a number of type specimens 
or at least cotype or paratype specimens of species 
described by W. Harper Pease and other con- 
chologists of the period. Dr. Dall states that he 
simply "corrected" the names of the specimens. 

It is unfortunate that we do not have more exact 
information concerning the acquisition of these 

'Part 1 on the life of (larrett. by W. Stephen Thomas, appeared 
in the previous number of The Nnntilnx. vol. 93. no. 1. pp. 1.5-28. 



early collections. For reasons best knovra to 
himself. Dr. Brigham made only meager record of 
early accessions. A search of Trustees records was 
made by Dr. Yoshio Kondo at the time he wrote a 
memorial to Dr. C. Montague Cooke, Jr., and he 
states that he found no information concerning the 
purchase of the Garrett (Ibllection. 

Prepared by E. H. Bryan, Jr. 

History of the Andrew Garrett Collection 

1888-1972 

Andrew Garrett died in Huahine, Society Islands, 
Nov. 1, 1887. His private collection of shells went 
on sale. 

February 18, 1893: Charles R. Bishop, in Wash- 
ington, D.C., wrote to Trustee Hyde [Bishop 
Estate Letters in. Book 4, pp. 56-58], notifying 
him that he had "authorized Mr. Dorence At- 
water to buy the Garrat [sic] collection of shells 
etc. at $5,000 if found to be in good order and 
complete . . ." 

May-October, 1893: Andrew Garrett collection 
received by the Bishop Museum. This date is 
deduced from Brigham 's correspondence between 
March and December, 1893, listing the Museum's 
needs to the Trustees. 

1894-1899: Collection was catalogued by Brigham 
(1894) and specimens were mounted, vnth 
printed labels, on cardboard. 

August, 1899: Wm H. Dall studied A. Garrett col- 
lection. See BPBM Director's Annual Report for 
1899 (Occas. Papers 1(2): 10-13). 

1900 ff.: Garrett collection was in the [exhibit] 
cases of BPBM (Director's Annual Report for 
1900, p. 8; "A Handbook for Visitors . . ." by 
Brigham, 1903). 

1905: Garrett Collection was partly relabelled in 
accordance with Dr. Dall's identification, and 
was rearranged to accord with the new system of 
taxonomic arrangement. (Director's Report for 
1905, p. 260). 



Vol. 93 (2-3) 



April 23. 1979 



THE NAUTILUS 97 



1927: Garrett's land Shells were removed from the 
showcases in Pobnesian Hall to the [Malacologj] 
laboraton,'. (C. M. Cooke, Jr., annual report to 
Director for 1927). 

1930: Mrs. J. G. McAllister copied "Garrett's 
original catalog into the Museum catalog . . ." (C. 
M. Cooke, Jr., Annual Report for 1930). [Mrs. 
McAllister did not, however, number the 
specimens with the corresponding catalog 
numbers; catalog numbers are 01-8694.] 

1930-1970: Garrett's specimens were rearranged, 
re-identified, re-surveyed, re-exhibited, etc., by 
various workers in malacology. 

1972 onward: Attempts are being made to locate 
possible types and to designate them as lec- 
tot\-pes by A. Kay and D. Fellows. We also hope 
to completely determine the circumstances by 
which the Museum acquired the collection. 

Prepared by: Danielle B. Fellows 
11 December 1972 

Geographic Names 

All of the type localities of Andrew Garrett 
were given along with the original descriptions. 
Certain of these names have changed with the 
passage of time and are listed below: 

Austral Islands are now Tubuai Islands. 

Cook's Islands are now Cook Islands. 

Kiva — This locality in the Fiji Islands has not 
been located. It has been suggested that this 
name may have been an error for "Kioa", a 
small island at the eastern end of Vanua 
Le\ai and northwest of Taviuni but Garrett 
had mentioned this locality several times as 
"Kioa shore reefe". It is possible that the 
name Kiva has since disappeared. The name 
Kiuva or Kiura has been suggested as well 
(about central on the coast at the eastern end 
of Viti Levu). 

Paumotu, Panmotu and Paumotus Seas or Is- 
lands are now Tuamotu Islands. 

Tivinni — is Taviuni or Taveuni Island. 

Viti Islands are Fiji Islands. 

Abbreviations 

AJC — American Journal of Conchology 
ANSP — Academy of Natural Sciences of Phil- 
adelphia 



BPBM — Bernice P. Bishop Museum 

BSMF — Bulletin Society Malac. France 

JANSP — Journal Academy Natural Sciences 
Philadelphia 

JC — Journal of Conchology 

PANSP — Proceedings Academy Natural Sci- 
ences Philadelphia 

PCANS — Proceedings California Academy Nat- 
ural Sciences 

PCAS — Proceedings California Academy Sci- 
ences 

PZS — Proceedings Zoological Society London 

Garrett included several manuscript names of 
W. H. Pease in the synonymy of other species by 
Pease. In a few cases, Garrett described the 
species with the original names. The credit for 
these species go to Garrett as he described them 
as well as added the figures. 

Pease, like many others during these early 
years of descriptive zoology, sent as gifts or ex- 
change a great deal of material with manuscript 
names, much of which was never described. Spec- 
imens under these names are in many institu- 
tions, both here and abroad, and Garrett's work 
will have solved many of these nomenclature 
problems for future workers. 



abbreriata. Cithara. 1873, PANSP. p. 223. pi. 3, fig. 41 

(Paumotus Isles). 
acuticostata, "Mousson" Garrett, Partula, 1884. JANSP, (2) 

9:30, pi. 2, fig. 13 a-b (Raiatea Island. Society Islands). 
adusta. Partula. 1884, JANSP, (2) 9:79 [A manuscript name in 

the sjTionymy of Partula varia Broderip.] 
affinis. Gibbida, 1872, PCAS, 4:201. (Viti and Samoa Islands). 
affinis. Nanina. 1887, BSMF, 4:4 [nomen nudum], (Isle 

Faiwata, Marquises at 2000 feet). [Is Microcystis subvenosa 

Ancey.] 
affims. Rissoina. 1873. PANSP, p. 212, pi. 2, fig. 10 (Viti Isles). 
affims. Tomatellina. 1879, PANSP, p. 23. [not fig.] (Rurutu 

Id., Austral Islands). 
dbopmKtatm, Goniobranchns. 1879. PANSP, p. 31. (Huahine, 

Society Islands). [Is Glossodoris Ehrenberg 1831.] 
altemata. Engina. 1872, PCAS. 4:203. (Samoa and Viti 

Islands). 
amanda. Odostomia. 1873, PANSP, p. 225, pi. 3, fig. 47, (Viti 

Islands). 
anceyana. Pitys. 1887, BSMF, 4:19, (I. le Dominique, Isles 

Marquises). [F^tys Beck 1837, [nomen nudum] ], is Diaglyp- 

tus Pilsbry 1893. 
angustivolata. Microcystis. 1884. JANSP, (2) 9:20, pi. 2, fig. 34, 

a-b. (Moorea Island. Society Islands). 



98 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2-3) 



anthmciria. Nassa, 1873, PANSP, p. 229. pi. 3, fig. 57, (Viti 

Isles). 
(Ltsavaeturis, Nanina. 1887, PZS, p. 169, (Naviti Island, Assawa 

Group, Viti Islands). 
assimilis. Mitra. 1873, PZS, p. 841 [not fig.] (Rarotonga, 

Samoa, and Viti Islands). 
assimilL% Trachomorpha. 1884, JANSP, (2) 9:27, pi. 3, fig. 44 

(Huahine Island, Society Islands). 
avenacea. Tnmcatella, 1887, PZS. p. 301 [not fig.] (Vanua 

Levu [Island], Viti Islands). 
hiaihr. Prirtula. 1884, JANSP. (2) 9:79, [A manuscript name 

in the synonymy oiPartula varia Broderip]. 
bicoUrr. Tiimada. 1880, JC. 3:38, [not fig.) (Samoa and 

Paumotu Islands). 
boraborensts. Pitys. 1884, .JANSP, (2) 9:32, pi. 2, fig. 18. a-b, 

(Borabora Island. Society Islands). 
bythineUaefirnnis. Atmpis. 1884, JANSP. (2) 9:98. pi. 3, fig. 73, 

(Tahiti and Moorea Islands, Society Islands). 
bythinaeformis. "Mirussim" Garrett, Omphalotropis. 1887. PZS, 
p. 310 [not fig.] (Vanua Balavo, Windward Islands, Viti 
Islands). 
caelata, Oathurella, 1873, PANSP, p. 220. pi. Z fig. .34. (Viti 

Isles). 
caelata, Vitrinella, 1873, PANSP, p. 214, pi. 2, fig. 16, (Kiva 

Island. Viti Isles). 
canalis, Pitys. 1872, AJC, 7:227. pi. 19, fig. 17, (Rarotonga 

Island. Cook's Isles). Lectotype (by Solem) in ANSP 477.52. 
cmtanea. Turricula, 1880, JC, 3:42, [not fig.] (Samoa and Viti 

Islands). 
cavemula, Pitys. 1872, AJC, 7:226, pi. 19, fig. 16 (Rarotonga 
Id., Cook's Isles [Cook Ids.] ). [Tryon had changed this name 
to Helix mbcavemuLa in error — non cavemula Hombron 
and Jacquinot 1841; Garrett had described his species in the 
genus Pitys and not Helix.] 
cnmanguineiis, Melampm. 1887. PZS, p. 287 [not fig.] (Vanua 

Levu Island, Viti Islands). 
consubrina, Pitys, 1884, JANSP, (2) 9:31, pi. 2, fig. 17. a-c 

(Huahine Island, Society Islands). 
consobrina, Plecotrema, 1873. PANSP, p. 236, pi. 3, fig. 69, 

(Viti Isles). 
ccmtigua. Microcystis. 1887, BSMF, 4:6 (lile Dominique, Isles 

Marquises). 
costata, Adf-nrhis, 1856 [1857], PCANS, 1:103 (Hawaii (Island], 

Hawaiian Islands). 
costatogranosa, Rissoim, 1873, PANSP. p. 211. pi. 2. fig. 7. 

(Viti Islands). 
costulatum. Caecum, 1873, PZS, p. 789. (Kioa Island. Viti 

Islands). 
crassilabrum, Rulimus. 1872, AJC, 7:233, pi. 18, fig. 5, (Vanua 

Levu Id. Viti Isles). 
craxsilabrum. Rissoa, 1856 [1857], PCANS, 1:102 [not fig.] 

(Hilo, Hawaii Id., Hawaiian Islands). 
erebristriaXuii. Melampus, 1887, PZS, p. 289 [not fig.] (north 

coast of Vanua Levu [Island], Viti Islands). 
erenilahrix. Cheletrnpi,% 1873, PANSP. p. 215, pi. 2, fig. 18, 
(Paumotus Islands). [Tryon puts Cheletropis in the 
synonomy of Sinuxiijern d'Orb. The.se are pelagic larvae of a 
marine gastropod. Garrett's figure, however, does not show 
any outer lip embayments. [WJC]. 



cretacea. Endndmta. 1884. JANSP. (2) 9:41. pi. 2. fig. 27, a-b 

(Borabora Island, Society Islands). 
crispa, Mitra (CosteUaria). 1872, PCANS, 4:201 (Samoa and 

Viti Islands). 
crystallim, Odostmnia. 1873, PANSP, p. 226, pi. a fig. 49 (Viti 

Isles). 
crystallina, ?Rissoa, 1873, PANSP. p. 216, pi. 2. fig. 24 (Kiva 

Island, Viti Isles). 
curta, Chnphalotropis, 1879, PANSP, p. 28, [not fig.] (Rurutu 

Id.. Austral Islands). 
cuspidata, Odustomia, 1873, PANSP, p. 228. pi. 3. fig. 54 (Viti 

Isles). 
daedalea. Oathurella, 1873. PANSP, p. 219. pi. 2. fig. .33 (Viti 

Isles). 
debilh Rissoim, 1873, PANSP. p. 212, pi. 2. fig. 9 (Viti Isles). 
decorticata, Pitys, 1872, AJC, 7:228. pi. 19. fig. 19 (Rarotonga 

Id., C<»k's Isles. [Cook Ids.]). Lectotj'pe (by Solem) in 

ANSP 477.54. 
degagei. Pttys, 1879, PANSP. p. 18 [not fig.] (Rurutu Id.. 

Austral Islands). 
degagei, Succinea, 1879, PANSP. p. 26 [not fig.] (Rurutu Id., 

Austral Islands). 
denseco,stata, Odostomia, 1873, PANSP, p. 223, pi. 3, fig. 42 

(Samoa and Viti Isles). 
densestnata. Odostomia. 1873, PANSP, p. 224, pi. 3. fig. 44 

(Viti Isles and Samoa). 
discoidiae. Microcystis. 1881, JANSP, (2) 8:409 [error for M. 

discordice Garrett]. 
discorxiice. Microcystis, 1881, JANSP, (2) 8:383 [not fig.] 

(Cook's Islands). 
ebumea, Mitra, 1880, JC, 3:15 [not fig.] (Paumotu Islands). 
ebumostoma, Mitra. 1880. JC, 3:1.5. [not fig.] (Paumotu 

Islands). 
erigua, Murex. 1856 [1857], PCANS, 1:102 [not fig] (Pure- 
shallow P<x)ls: on the rock>- coasts of Hawaii). 
exqvidta, Thahu 1872, PCANS, 4:202 [not fig.], (Paumotu 

Islands). 
exquisita, Mitra, 1872 [April 1893). PZS. p. 842 [not fig.], 

(Paumotu, Tahiti. Cook's Islands. Samoa and Viti Islands). 
eiilis, Odostomia 1873, PANSP. p. 223, pi. 3. fig. 43 (Viti 

Isles). 
fenestrata. FwsureUa 187a PCANS, 4:'204 [not fig.], (Viti and 

Samoa Lslands). 

festiva, Turricula 1880, JC, 3:46 [not fig.] (Viti klands). 

ficta Endodfinta. 1884, JANSP. (2) 9:41 [Nomen nudum, 
originally listed in the Schmeltz. Cat. Mus. Godeffroy 5:223 
and renamed £! cretacea Garrett, q.v.] 

filaris. Cmdhanus, 1872, PCANS, 4:202 [not fig.], (Samoa and 

Viti Islands). 
J}ericostata, Turricula, 1880, JC, 3:46 [not fig] (Paumotu and 

Viti Islands). 
foveolata. PissureUa, 1872, PCANS, 4:203 [not fig.] (Viti and 

Samoa Islands). 



'Pure may have meant Puna but the word in Hawaii;ui does not 
mean "shallow pools". Data from Dr. Lee Moettler of the B. P. 
Bishop Museum. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 99 



fraiemda, Mitra. 1872, [April, 1873], PZS, p. 842 [not fig.] 

(Tahiti, Rarotonga, Samoa and Viti Islands). 
fiiscmigra, Turricula, 1880, JC, 3:47 [not fig.] (Kioa shore 

reefs, Viti Islands). 
fitsifimnis. Daphnella. 1873, PANSP, p. 229, pi. 3, fig. 58 

(Paumotus Isles). 
gibbosa. Engma. 1872, PCANS, 4:203 (Viti and Samoa 

Islands). 
godeffroyana, Nanina, 1872, AJC, 7:223, pi. 19, fig. 9 (Interior 

of the N. E. part of Vanna Levu, Viti Isles). 
geomeaensis. Heiicina, 1893, PANSP, p. 233, pi. 3, fig. 63 

(Gomea Island, Viti Isles). 
gracilis. Rissoina. 1873, PANSP, p. 211. pi. 2, fig. 8 (Viti and 

Society Isles). 
granum. Truncatella. 1872, AJC, 7:225 [not fig.] (N. E. end of 

Tavinni Id., Viti Isles). 
gregana. Libera. 1884. JANSP, (2) 9:136, pi. 2, fig. 6, a-b 

(Moorea Island. Society Islands). 
guanensis. Bulimus, 1872, AJC, 7:235, pi. 18, fig. 8 (Guan Isl., 

Viti Isles). 
gummea. Trochonanina, 1887, BSMF, 4:14 (lile Nuka-Hiva, 

lies Marquesas). 
han-eyensis. Pitys. 1872, AJC, 7:228, pi. 19, fig. 20 (Rarotonga 

Id., Cook's Isles [Cook Ids.]). Lectotype (by Solem) in 

ANSP 477.56. 
hirsuta. Plecotrema. 1872, AJC, 7:219, pi. 19, fig. 2 (Viti 

Islands). 
holosericea, Neritina. 1872, AJC, 7:219, pi. 19, fig. 1 (Vanna 

Lavu, Viti Islands). 
horrida. Rissoina. 1873, PANSP, p. 210, pi. 2, fig. 5 (Viti 

Islands). 
hoyti. Bulimus. 1872, AJC, 7:234, pi. 18, fig. 7 (Vanna Levu 

Id.. Viti Isles). 
hoyti. Nanina, 1872, AJC, 7:221, pi. 19, fig. 6 (Tavinni Id., Viti 

isles). 
hoyti. Tumcida, 1880, JC, 3:47 [not fig.] (Viti Islands). 
huaheinensis. Partida, 1884, JANSP, (2) 9:78 [A manuscript 

name in the synonymy ofPartula varia Broderip]. 
humeralis. Mitra, 1880, .JC, 3:18 [not fig.] (Anaa Island, 

Paumotu Islands). 
hyaixna. missoa. 1873, PANSP, p. 217, pi. 2, fig. 25 (Samoa, 

Viti and Paumotus Isles). 
hyaliniis. Obeliscus. 1893, PANSP, p. 228, pi. 3, fig. .56 

(Paumotus and Society Isles). 
imperfirrata. "Pease" Garrett. Partida. 1884, JANSP, (2) 9:.54, 

pi. .3, fig. 53 (Toloa and Hapai Valleys, west coast of Raiatea 

[Island] Society Islands). 
indsa, Tarricula, 1880. JC, 3:63 [not fig.] (Kioa shore reefs, 

Viti Islands). 
incisus. Melampus. 1887, PZS, p. 289 [not fig.] (Vanua Levu 

[Island] Viti Islands). 
iilfrastncta Rissoa, 1873, PANSP, p. 215. pi. 2, fig. 21 (Kiva 

Island, Viti Isles). 
injrasulmta. CMhurella. 1873, PANSP, p. 220, pi. 2, fig. 35 

(Viti Isles). 
instricta, Turricula, 1880, JC, 3:48 [not fig.] (Viti Islands). 
irregularis. Patula, 1887, PZS, p. 179 [not fig.] (Viti Levu, Viti 

Islands). Lectotype (by Solem) in BPBM 7982. 



kantavuenxis, Trochomarpha, 1887, PZS, p. 177 [not fig.] (Kan- 

tava Island, Viti Islands). 
kivaensis. Nanina, 1873, PANSP. p. 237, pi. 3, fig. 71 (Kiva 

Island, Viti Lsles). 
koroensis. Bulimus. 1872, AJC, 7:236, pi. 18, fig. 9 (Koro Isl., 

Viti Isles). 
laeiicostata, Tiirricula, 1880, JC, 3:50 [not fig.] (Paumotu 

Islands). 
lamellwosta, Patula, 1884, JANSP, (2) 9:30, pi. 2, fig. 11, a-b 

(Tahiti Island, Society Islands). Lectotype (by Solem) BPBM 

2841. 
lento, Microcysti'!, 1887, BSMF, 4:5 (I. le Dominique, I. les 

Marquises). 
laynrdiana. Oniphalotropis. 1887, PZS, p. 310 [not fig.] (Vanua 

Balavo [Mbalavu], Windward Islands [Fiji Islands] ). 
lentiginnsa. Pythia, 1872, AJC, 7:220, pi. 19, fig. 4 (Tavinni Id. 

Viti Isles). 
Libera 1881, JANSP, (2) 8:.390 [no type species indicated]. 
liricincta, Vitnnella. 1873, PANSP, p. 213, pi. 2, fig. 14 (Kiva 

Island, Viti Isles). 
littarinaeformis, ?Rissoa 1873, PANSP, p. 215, pi. 2, fig. 18 

(Kiva Island, Viti Isles). 
lutea, Odostomia. 1873, PANSP, p. 226, pi. 3, fig. .50 (Viti 

Isles). 
luteofusca, Mitra, 1872 [1873], PZS, p. 842 [not fig.] 

(Rarotonga, Cook's Islands). 
marquesana, Pitys, 1887, BSMF, 4:18 [not fig.] (Nuka-Hiva, I. 

les Marquesas). 
marqiiesana, Suecirwa, 1887, BSMF, 4::B7 [not fig.] (I. le 

Dominique, I. les Marqueses). 
maupiensis, Pitys, 1872, PCAS, 4:204 [not fig.] (Mautipi 

Island, Society Islands). 
maupiensis. Pitys, 1873, PANSP, p. 233, pi. 3, fig. 64 (Maupiti 

Island, Society Isles). 
melanostoma, Cithara, 1873, PANSP, p. 222, pi. 2, fig. 40 (Kiva 

Island, Viti Isles). 
rnelanostoma, Persa. 1872, AJC, 7:224, pi. 19, fig. 11 fV'iti 

Isles). 
merzianoides. Helix (Trochomarpha), 1872, PANSP, p. 237, pi. 

3, fig. 72 (Vanna Levu Island, Viti Isles). 
micans, Tcimatellina. 1879, PANSP, p. 23 [not fig.] (Rurutu 

Id., Austral Islands). 
milleciistata Rissoina, 1873, PANSP, p. 210, pi. 2, fig. 3 (Viti 

Islands). 
mdlegrana Daphnella, 1873, PANSP, p. 230, pi. 3, fig. .59 

(Paumotus Isles). 
miruyr, Hipponix (Amalthea). 1856 [18.57], PCANS, 1:103 [not 

fig.] (Hawaii [Island], Hawaiian Islands). 
minutissima. DriUia, 1873, PANSP, p. 218, pi. 2, fig. .30 (Viti 

Isles.) 
modicella, Turricula, 1880, JC, 3:53 [not fig.] (Paumotu 

Islands). 
monticola, Heiicina, 1887, BSMF, 4:42 (I. le Dominique, I. les 

Marqueses). [Nomen nudum, \s Heiicina versihs Ancey] 
mooreana, Zonites, 1884, JANSP, (2) 9:23, pi. 2, fig. 28, a-b 

(Moorea Island, Society Islands). 
midticostata, Rissoa, 1856 [1857], PCANS, 1:103 [not fig.] 

(Hilo, Hawaii Id., Hawaiian Islands). 



100 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



mulHlamMata. Pitys. 1872. AJC. 7:230. pi. 19, fig. 2.5 

(Rarotonpa Id.. Cook's Isles [Cook Ids] ). 
muHUuieata, Turbo. 18.56 [1857], PCANS, 1:102. [not fit;.] 

(Hilo Bay. Hawaii Id.. Hawaiian Islands). 
multistriata, \anina. 1887. RSMF, 4:12 (I. le Taiwata. I. les 

Marqueses). [Nomen nudum] 
newcombittnum. Succinea. 1^56 [1857]. PCANS. 1:103 [not fig.] 

(Disctrict of Waimea [Oahu Id.] Hawaiian Islands). 
nigricans, Turricula, 1880. JC, 3:47 [Nomen nudum, is Tur- 

riculafusconigra Garrett.] 
nodosa. Vitrinetla. 1873. PANSP, p. 214. pi. 2. fig. 17 (Viti 

Isles). 
obeliicus, Odostomia. 1873. PANSP, p. 226, pi. 3, fig. 51 (Viti 

Isles). 
obesa. Atropis. 1884, JANSP, (2) 9:99, pi. 3. fig. 72 (northwest 

part of Tahiti [Island]. Society Islands). 
obesa, Claihimlla, 1873. PANSP, p. 221. pi. 2. fig. ;36 (Viti 

Isles). 
ochrostnma, Bulirmis. 1872. AJC. 7:232. pi. 18, fig. 3 (Tavinni 

Island. Viti Islands). 
octolamellata. Pttys. 1887, BSMF, 4:18 [not fig.] (I. le Domini- 
que, I. les Marqueses). 
(rryza. Odostomia, 1873, PANSP, p. 224, pi. 3, fig. 45 (Kiva 

Island, Viti Isles). 
oryza. RissuiTia, 1873, PANSP, p. 210. pi. Z fig. 4 (Kiva Island. 

Viti Islands). 
otareae. Nanina, 1872, AJC, 7:222, pi. 19, fig. 8 (Natawa Bay, 

Vanna Levu [Fiji Islands]). 
otareae. Pitys. 1872, AJC, 7:228, pi. 19, fig. 21 (Rarotonga Id.. 

Cook's Isles [Cook Ids.] ). Lectotype (by Solem) ANSP 477.55. 
paliuiosu.% Ophicardelus. 1872. AJC, 7:220, pi. 19, fig. 3 (Viti 

Islands). 
papilla<<a. [Mllia. 1873, PANSP, p. 218, pi. 2, fig. 29 (Viti 

Islands). 
paumotuensis. Sciss^irella, 1873, PZS. p. 878 [not fig.] 

(Paumotu Islands). 
peaseana, Tomatellina, 1884. JANSP. (2) 9:83. pi. 2. fig. 19 

(Moorea Island. Society Islands). 
jjenseii, Dirricnln. 1880..JC.3:.57 [not fig.] (Viti Islands). 
periivata, Pythm. 1872, AJC, 7:221, pi. 19, fig. 5 (Viti Isles). 
perpiexa. Partida. 1884, JANSP, (2) 9:79. [Nomen nudum, in 

the synonymy of Partida varia Broderip, in Garrett.] 
perpiexa. Tomatellina, 1879, PANSP, p. 24 [not fig.] (Rurutu 

Id., Austral Islands). 
pieea, Endodonta fabrefacta var., 1884, JA.NSP, (2) 9:39, [not 

fig.) (W. side of Raiatea Island, Society Is ands). 
picturata. Nai-u-ella. 1872, AJC, 7:224, pi. 19, fig. 13 (Vanna 

Levu, Viti Isles). 
pirujtm. Ckithurella. 187.3, PANSP, p. 221, pi. 2, fig. 38 (Samoa 

and Viti Isles). 
pimjuix. Partida. 1884, JANSP, (2) 9:77 [not fig.] (mountain 

ravines at the head of Vaioara Valley, Raiatea Id., Society 

Islands). ["It certainly = rustica" [Garrett]. A manascript 

name in the synonymy of Partula rustica Pease.] 
planoconiut 'Mousson' Garrett. Trochomorpha, 1887. PZS, p. 
174 (Ono Island, Viti Islands). [This was a ms. name by 
Mousson, which Garrett described.] 
plano.fpira, Patula. JANSP. (2) 8:388 [not fig.] (Rarotonga 
Island. ('<K)k's Islands). Lectotype (by Solem) in Zool. Mus. 
Univ. Zurich. 



pfMiana. Helicina. 1887. PZS. p. 313 [not fig] (Viti Levu [Fiji 

Islands]). 
praj!ina. Gibbxda, 187^ PCANS. 4:202 [not fig.] (Viti Islands). 
proputqua. Mitra, 1880. JC. 3:22 [not fig.] (Society Islands). 
propinqua. Turricula, 1880. JC. 3:58 [not fig.] (Viti Islands). 
prorima, Pitys. 1872. AJC. 7:230. pi. 19. fig. 21 (Rarotonga Id.. 

Cook's Isles [Cook Ids] ). Lectotype (by Solem) in ANSP 

47700. 
pulchra. OdostomicL, 1873. PANSP. p. 225, pi. 3, fig. 48 (Viti 

Isles), 
pulchra. Turricula. 1880, JC, 3:56 [not fig.] (Viti and Samoa 

Islands). 
pidchella, Clathurella, 1873, PANSP, p. 219, pi. 2, fig. 32 (Viti 

Isles). 
punctifera, Clathurella, 1873, PANSP, p. 222, pi. 2, fig. 39 

(Society, Samoa and Viti Isles). 
punctifera. Microcystis. 1879, PANSP. p. 17. [not fig.] (Rurutu 

Id.. Austral Islands). 
punctiperforata, Pitys. 1884. JANSP. (2) 9:.32. pi. 2, fig. 16. a-c 

(Moorea Island. Society Islands). 
pura. Microcystis. 1887. BSMF. 4:5 [not fig.] (I. le Dominique. 

I. les Marqueses). 
pura. Vitrinetla. 1873. PANSP. p. 213. pi. 2. fig. 13 (Kiva 

Island, Viti Isles). 
pusUla, Drillia. 1873, PANSP, p. 219. pi. 2. fig. 31 (Viti Isles, 

Cook's Isles, Paumotus Isles). 
pygmaea. Volvaria (Volvarina), 1873, PANSP, p. 217, pi. 2, fig. 

27 (Viti Isles). 
(juadricarinala, Separatista, 1873, PZS, p. 878 [not fig.] 

(Paumotu Islands). 
rad>ata Pease] PaHnia, 1884, JANSP, (2) 9:74, pi. 3. fig. 45 

(Hamoa Valley, east coast of Raiatea Island, Society 

Islands). 
raiatensis. Helicina. 1884. JANSP. (2) 9:106. pi. .3. fig. 69. a-b 

(Raiatea [Island]. Society Islands). 
1-aiatensis. Partula, 1884. JANSP. (2) 9:54. [Nomen nudum, in 

the synonymy of Partida imperforata "Pease" Garrett . q.v.] 
rambiensis. Bulimus. 1872. AJC. 7:233. pi. 18. fig. 4 (Rambi 

Id.. Viti Isles). 
recedens. Libera. 1884. JANSP. (2) 9:36. pi. 2. fig. 7 (Moorea 

Island. Society Islands). 
reticulata, Pleurotoma (Mangelia). 1856 [1857], PCANS, 1:102 

[not fig.] (Hilo Bay, Hawaii, Hawaiian Islands). 
Rissopsis. 1873, PANSP, p. 228, type species Rissopsis typica 

Garrett, (monotypic). 
rudi.'i. Pitys. 1872. AJC. 7:227. pi. 19. fig. 18 (Rarotonga Id.. 

Cook's isles [Cook Ids.]). LectotjT)e (by Solem) in ANSP 

47701. 
riigatus. Bidiniiis. 1872. AJC. 7:234. pi. 18. fig. 6 (Vanna Levu 

id..VitiLsles). 
ran(0«7i.s-i.s'. Piitula. 1879, PANSP, p. 18 [not fig.] (Rurutu Id.. 

Austral Islands). 
riLsticus. Melampii.':. 1887, PZS. p. 289 [not fig.] (Viti Islands 

and on Tonga and Samoa Islands). 
scaha, Ri.osoma, 1873. PANSP. vol. 25. p. 211. pi. 2. fig. 6 (Viti 

Islands). 
scatpta. Microcystis. 1884. JANSP. (2) 9:21. pi. 2. fig. 30. a-b 

(TahiiJi Island. Society Islands). 
.^rhmeltziann, Zoitites. 1887. PZS. p. 173 (Malolo Island. Viti 

Islands). [Is in the genus (>rpiella.] 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 101 



sa-ipta. Bulla, 1856 [1857]. PCANS, 1:103 [not fip.] (Hilo. 

[Hawaii Id.]. Hawaiian Islands.) 
sculptili'!. Rissmm. 1873, PANSP, p. 209, pi. 2, fig. 2 (Viti 

Islands). 
sculptUi.% Vitrinella. 1873, PANSP, p. 214, pi. 2, fig. 15 (north 

coast of Natawa Bay, Vanna Levu, Viti Isles). 
semilmeata. Oathurcllu. 1873, PANSP. p. 221, pi. 2, fig. 37 

(Samoa and Viti Isles). 
simidans. Helicim. 1884, JANSP, (2) 9:105, pi. 3. fig. 66, a-b 

(Tahiti [Island], Society Islands). 
spiripuncta, Mitra. 1880, JC, 3:27 [not fig.] (Koro reefs, Viti 

Islands). 
steamseayia. Microcystis. 1887, PZS, p. 171 [not fig.] (Viti 

Islands). 
stellaris. Separatista, 1873, PZS, p. 879, (Samoa and Viti 

Islands). 
striata. Gibbida, 1872, PCAS, 4:201 [not fig.] (Viti and Samoa 

Islands). 
striaiella. Purpitra. 1856, [1857], PCANS. 1:102 [not fig.] 

(Island of Hawaii. Hawaiian Islands). 
striatula, Trochus. (Mm-garita). 1856 [1857], PCANS. 1:102 

(Hawaii [Island] Hawaiian Islands). 
strict^is. "Mousson" Garrett. Ostodes. 1887, PZS, p. .306 [not 

fig.] [See Clench 1949, B. P. Bishop Museum, Bull 196, p. 21, 

fig. (Holotype 8a)]. (Vatu Lele Island, ex museum Godef- 

froy) [Fiji Islands.] 
subcomda. Trockonanina, 1887, BSMF. 4:13 (I. le Dominique, I. 

lesMarqueses). 
subexcrescens. Microcystis. 1881, JANSP, (2) 8:381, (Rarotonga, 

Cook Islands). [Nomen nudum.] 
sitbglobosa. Succinea, 1884, JANSP, (2) 9:88, pi. 2, fig. 3 

(Tahiti [Island] Society Islands). 
subghboxiis. Pedipes. 1873, PANSP, p. 236, pi. 3, fig. 70 (Tan- 

thala Island, Viti Isles). 
subntfa "Pease" Garrett. Helicina, 1884, JANSP, (2) 9:104, pi. 

3, fig. 68, a-b (Raiatea and Borabora [Islands] Society 

Islands). 
subrugosa, Trochmumina, 1884, JANSP, (2) 9:22, pi. 2. fig. 38, 

a-d (Tahiti and Moorea [Islands] ). 
subtexturata, Mitra. 1880, JC, 3:26 [not fig.] (Raiatea Island, 

Society Islands). 
subtilis. Pitys. 1884, JANSP, (2) 9:31, pi. 2, fig. 15, a-c 

(Huaheine Island, Society Islands). 
s^dcata, Odostomia. 1873, PANSP, p. 224, pi. 3, fig. 46 (Viti 

Isles). 
supracostata, Rissoina, 1873, PANSP, p. 209, pi. 2, fig. 1 (Viti 

Isles). 
suturalis. "Pease" Garrett. Partula, 1884, JANSP, (2) 9:6.3, pi. 

3, fig. 77 (Haamene Valley, east coast of Tahaa [Island], 

Society Islands). 
tahitensis. Mitra. 1880, JC. 3:30 [not fig.] (Tahiti Island, Socie- 
ty Islands). 
tahitemis. Trockonanina, 1884, JANSP, (2) 9:23, pi. 2, fig. 39, 

a-c (Tahiti Island, Society Islands). 
taneae. Pitys. 1872, PCAS, 4:204 [not fig.] (Maupiti Island, 

Society Islands). 
taneae. Pitys. 1873, PANSP, p. 234, pi. 3, fig. 65 (Maupiti 

Island. Society Isles). 
tainnnietisis. Helix. 1872, AJC, 7:223. pi. 19, fig. 10 (Tavinni 

Id., Viti Isles). 



tPtiella, Nanina. 1872, AJC, 7:222. pi. 19, fig. 7, (Kioa Id.. Viti 

Isles). 
tenuicostata, Pitys, 1872, AJC, 7:229. pi. 19, fig. 23 (Rarotonga 

Id., Cook's Isles [Cook's Ids.] ). Lectotype (by Solem) in 

ANSP47702. 
terehra, Rissoina. 1873, PANSP, p. 212, pi. 2, fig. 11 (Viti and 

Samoa Islands). 
tessellata, Daphnella, 1873, PANSP, p. .330, pi. 3, fig. 61 

(Paumotus Isles). 
thdia, Partida. 1884, JANSP, (2) 9:69, pi. .3, fig. 46 (Huaru 

Valley, west coast of Raiatea Island, Society Islands). 
themis. Trcchomorpha. 1887, PZS, p. 177 (new name for 

Trochornorpha ludersi Mousson 1870, non Pfeiffer 18.55). 
trynni, Goniodaris. 1873, PANSP, p. 2.32. pi. 4 (Society Islands). 
tntncata, Rissoa. 1873, PANSP, p. 217. pi. 2. fig. 26 (Kiva 

Island, Viti Isles). 
tumuloides, Pitys. 1872, AJC, 7:225, pi. 19, fig. 15, (Rarotonga 

Id.. Cook's Isles [Cook Ids.] ). 
turrita. Plecotrema, 1873. PANSP. p. 235. pi. 3, fig. 68 (N. E. 

end of Tavinni [Taveuni Island] Viti Isles). 
turrita. Rissmrm. 1873, PANSP, p. 213, pi. 2, fig. 12 (Society 

Islands). 
typica, Rissopsis. 1873, PANSP, p. 228, pi. 3, fig. .55 (Viti and 

Samoa Isles). 
unilamellata, Pitys. 1873, PANSP, p. 235. pi. 3. fig. 67 

(Rarotonga Island, Cook's Isles). 
unilineata. Odostomia. 1873, PANSP, p. 227, pi. 3, fig. .53 (Viti 

Isles). 
unilineata, Turricula, 1880, JC, 3:60 [not fig.] (Viti Islands). 
ventricosa. Turricula, 1880, JC, 3:55 [not fig.] (Samoa and Viti 

Islands), [Nomen nudum]. [Is T porphyretica Reeve.] 
venusta, Rissoa, 1873, PANSP, p. 216, pi. 2, fig. 23 (Viti Isles). 
vidmUndes. Drillm. 1873, PANSP, p. 217, pi. 2, fig. 28, (Viti 

Isles). 
riolacea. Thala. 1872, PCAS, 4:202 (Samoa and Viti Islands). 
virginea, "Pease" Garrett, Partula, 1884, JANSP, (2) 9:61, pi. 

3, fig. 54 (Vaipiti Valley, west coast of Tahaa [Island] Socie- 
ty Islands). 
vitiarm, Paludinella, 1872, AJC, 7:224. pi. 19, fig. 12 (Viti 

Isles). 
vitiense. Caecum, 1873, PZS, p. 879 (Kioa Island, Viti Islands). 
vitiensis. Assiminea. 1872, AJC, 7:'225, pi. 19, fig. 14 (Viti 

Isles). 
intiensis, Placostylus, 1887, PZS, p. 184 [not fig.] (Na Viti 

Levu Bay, N. E coast of Viti Levu, Viti Islands). 
litiemis. Pupina. 1873, PANSP, p. 233, pi. 3, fig. 62 (Gomea 

Island, Viti Isles). 
ritrea. Daphnella, 1873, PANSP, p. 230, pi. 3, fig. 60 

(Paumotus Isles). 
vitrea, Odostomia. 1873, PANSP, p. 227, pi. 3, fig. 52 (Viti 

Isles). 
ritrea. ?Ri%'ioa. 1873, PANSP, p. 215, pi. 2, fig. 19 (Kiva Island, 

Viti Isles). 
woapoensis, Pitys, 1887, BSMF, 4:17, (1. le Woapo, I. les Mar- 

queses). 
youngi, Pitys, 1872, AJC, 7:229, pi. 19, fig. 22 (Rarotonga Id., 

Cook's Isles [Cook Ids.] ). Lectotype (by Solem) in ANSP 

47703. 
zebra. Strigatella. 1880. JC. 3:35 [not fig.] (Viti and Samoa 

Islands). 



102 THE NAUTILUS 



April 23, 1979 



Vol. 93 (2) 



zehrina. Mitra. 1872 [187.3] PZS. p. »42, [not fig.] (Paumotu. 

Tahiti. Cook's [Islands], Samoa. Viti Islands). 
zebrina. Pitys. 1873. PANSP, p. 234, pi. .3. fig. 66 (Rarotonga 

Island. Cook's Isles). 

Additional Names by William Harper Pease 

These names were inadvertently omitted by W. 
J. Clench (1975), Nemouria, no. 16, Delaware 
JMaseum of Natural History. 

apprurinintn Pease. PiiriuUu 1884, .JANSP, (2) 9:7.5 [nomen 
nudum]. [Is P. inttata Pea.se. It was listed earlier by Glo>Tie 
in the Journal of Conchology. 1:338. May. 1878]. 

microsUima Pease, Partida. 1884, JANSP, (2) 9:74 [nomen 
nudum]. [Is P. radiata "Pease" Garrett, lyr] 

fraterntld Pease, Helix, 1867, AJC, 3:104. [New name for 
Helix sadptilis Pease, 18&5, non Bland 1858.] 

oimlaiifiixis "Pea.se" Tryon. Milmiiu. 18«i. A.JC. 2:299. pi. 2f), 
fig. 4 (Oualan I. [now Kusaie Island. Caroline Islands.]). [A 
manuscript name by Pease but never described by him.] 

IMoIluscan Bibliography of Andrew Garrett 

1856 [1857] "On New Species of Marine Shells of the Sand- 
wich Islands." Pmc. California Acad. Nat. Sci.. 1:102-103. 

1872 a. "Descriptions of New Species of Shells from the South 
Sea Islands." Pmc. California Acad. Sci., 4:'201-204. 

1872 b. "Descriptions of New Species of Land and Freshwater 
Shells." ^IniCT-. J. Conch., 7:219-230. pi. 19. 

1872 c. "List of Species of Bulimus Inhabiting the Vili 
Islands, with Notes on Their Geographical Range, and 
Descriptions of New Species." Amer. J. Conch. 7:231-236, pi. 
18. 

1873 a. "Descriptions of New Species of Marine Shells In- 
habiting the South Sea Islands." Proc. Acad. Nat. Sci. 
Philadelphia, pp. •2(J9-231. pi. 2-3. 

1873 b. "Description of a New Species of Goniodoris." Proc. 
Acad. Nat. Sci. Philadelphia, p. 232, pi. 4. 

1872 [1873 c] "List of the Species of Mitridae Collected at 
Rarotonga, Cook's Islands, with Notes, also with Descrip- 
tions of New Species." Pmc. Zool. Soc. London, pp. 839-843. 

1873 d. "Description of New Species of Land Shells Inhabiting 
the South Sea Islands." Pmc. Acad. Nat. Sci. Philadelphia, 
pp. 233-237, pi, 3. 

1872 [1873 e.] "Description of a New Species of Scissurella 

from the Paumotu Islands." Proc. Zool. Soc. London, pp. 

878-879. 
1872 [1873 f.] "Descriptions of Two New Species of Caecum 

from the Viti Islands." Pmc. Zool. Soc. London, p. 879. 
1872 [1873 g.] "Descriptions of Two New Species of 

Separatista." Pmc. Zml. Soc. Limdon. p. 878 [Paumotu 

Islands]. 
1878 a. "Occurrence of Gadinia reticulata Sow., in 

Southeastern Polynesia."./, of Conch. 1:335. 



1878 b. "Occurrence of Crepidula aeuleata Gmel., in the Mar- 
queses Islands." J of Conch. 1:335-336. 

1878 c. "Annotated Catalogue of the Species of Conus Col- 
lected in the South Sea Islands." J. of Conch. l:3,53-.367. 

1879 a. "List of I.and Shells Inhabiting Rurutu. one of the 
Austral Islands, [Tabuai Ids.] with Remarks on Their 
Synonymy, Geographical Range and Descriptions of New 
Species." Proc. Acad. Nat. Sci. Philadelphia, pp. 17-30, [pp. 
17-24, March 25, 1879; pp. 25-30, April 15, 1879]. 

1879 b. "Description of a New Species of Goniobranchus." 
Proc. Acad. Nat. Sci. Philadelphia, p. 31. 

1879 c. "Annotated Catalogue of the Species of Cypraeidae 
Collected in the S. Sea Islands."./ of Conch., 2:105-128. 

1880 "Catalogue of the Polynesian Mitridae, with Remarks on 
Their Geographical Range, Station and Descriptions of Sup- 
posed New Species." J. of Conch.. 3:1-7.3, [pp. 1-32, Jan. 
1880; pp. 33-73, April 1880]. 

1881 "The Terrestrial Mollusca Inhabiting the Cook's or 
Hervey Islands." Jour. Acad. Nai. Sci. Philadelphia, (2) 
8::381-411. 

1884 "The Terrestrial Mollusca Inhabiting the Society 

Islands." .Jcmr. Acad. Nat. Sri. Philadelphia, (2) 9:17-114, pi. 

2-3. 
1887 a. "On the Terrestrial Mollusks of the Viti Islands. Part 

I." Proc Zool. Soc. London, pp. 164-189 [June 1, 1887]. 
1887 b. "Mollusques Terrestres des lies Marquises." Bull. Soc. 

Maine. France, 4:1-48. 
1887 c. "On the Terrestrial Mollusks of the Viti Islands, Part 

II." Proc. Zool. Soc. London, pp. 284-316 [Aug. 1. 1887]. 
1887 d. "The Terrestrial Mollusca Inhabiting the Samoa or 

Navigator Islands." Proc. Acad. Not. Sri. PhiUidelphia, 

39:124-1.53. 



Acknowledgments 

I wish to thank Mr. Edwin H. Bryan for data 
on place names and for the history on the Andrew 
Garrett Collection and to Danielle B. Fellows for 
the chronological data on the collection. To Dr. 
Yoshio Kondo for xerox copies about Andrew Gar- 
rett held in the library of the Bemice B. Bishop 
Museum. To Mary Anne Quilty, I am most grate- 
ful for typing the manuscript and for several help- 
ful suggestions. 

My thanks are due to Dr. Joseph Rosewater of 
the National Museum of Natural History for 
checking the publications of Andrew Garrett in 
the department of Mollusks. 



Vol. 93 (2-3) 



April 23, 1979 



THE NAUTILUS 103 



THE CAECIDAE (GASTROPODA: RISSOACEA) 
OF WATER ISLAND, U. S. VIRGIN ISLANDS, WITH A NEW SPECIES. 

Hugh J. Mitchell-Tapping' 

Department of Geology 

The Florida State University 

Tallahassee, Florida 32306 

ABSTRACT 

Eleven shallow-icater species of C-decum, from the marine sediment aronnd Water 
Island, are described according to their microsculpture as observed under the scan- 
ning electron microscope. One new species, Caecum donmoorei. irhich was found in 
Sprat Bay. Water Island. ?.s also described. 



In 1973, a study was made of the shallow ma- 
rine carbonate sediment around Water Island, 
the fourth largest island in the U. S. Virgin Is- 
lands group. A total of 56 samples of approxi- 
mately 100 grams each was collected around the 
island at sites which were exposed to differing 
amounts of wave-energy. A total of 618 Caecidae 
was picked from the samples and their distribu- 
tion around the island was plotted according to 
the number of specimens found (Fig. 1). 



~-\ 


St. Thomas 




/—^ 


; 


/^ 


-■ . 


-^^ 


Jy^ 


( ,— -V 


s:^ 




N^ 


""-^ ( o \ 


\ o 


.s^^ 






\ *^ 


/ \( 


^ 


CROWN BAY 




/ /\ 


\ 




II .10 




/ / \ 


1 


46jts 


V*v«o 


\ yv 


( ^ 


-^ .^- 


isl/ 


K 


.7 -^ yh- \ 


V/ 


^^ 12./ 


.•** 




y^\ \% \ 


^-~^ 






hA \ P- \ 




( 

roe 

1» •^ 


• 5 ?> 


6 .6, 


IV. <r .9 


■o 


1 5*] 

.1 IJ 


Vi4 o 


10^ 
10.16^ 


5 ^" L 


26? 




9V^i>^ 


/ 




I9» 




I7»"V^ 
ll» 50\. 


1 








O /•lo 


' ' 






'T 


/ 




T^^^^lf^^^ 


"k 


^^•6 


N 


.5KM 




I0« 


• 5 SCALE 







FIG. la. Ih.stnbutiim of the number of xpeciiiienn collected 
around Water Island, U. S. Virgin Island-t. Stippled areas are 
grassbed, low wave-energy areas. 



• 




y^ ^. i iMm 


ffM al^^p& 




( 






• o • • 



'Present address: 6101 Warwick Qiurt, New Orleans, La 70114. 



FIGS. 1-8. 1, C. breve Foliii Xlo: 2, C. breve Folin X120: 
3, C. imbrieatum Cm-penter X15; 4, C. imbricatum Carpenter 
X120; 5, C. tenuicostatum Folin X^O; 6, C. tenuicostatum 
Folin X215; 7, C. tenuicostatum Folin X1.5; 8, C. tenuicosta- 
tum Folin XUO. 

Compared with samples from Bahia Honda 
in the Florida Keys, where up to 212 specimens 
per sample occur, there are few specimens in this 
area. This may be due to the geographical loca- 
tion of the Virgin Islands and the prevailing east- 
west current. This current results in the speci- 
mens being representative of the local standing 
crop only. It is interesting to note that not a sin- 
gle specimen of Caecum in.sulanon Moore, origin- 
ally found on the sister island of St. John (Moore, 
1970), was present in Water Island samples. 



104 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



^^^^^^? 


4 ^^^^^^^^^^^v i^l^^^^^^^^^H 


^^^ 





FIGS. 9-16. 9, C. regulare Carpenter X25: 10, C. regulare 
Carpenter X175: 11, C. textile Fniin Xii5: 12, C. textile Folin 
XSiO; 13, C. cornucopiae Carpenter X15; 14, C. comucopiae 
Carpenter X2i0; 15, C. gurgulio Carpenter X20: 16, C. gur- 
gulio Carpenter X160. 

The distribution of the 618 specimens (Fig. 1) 
shows no discriminate pattern, other than the 
low count for the eastern side of the island. This 
small number of specimens might be attributed 
to the local water current through Gregerie 
Channel, which would move the specimens to a 
lower energy area. The dominant species in the 
grass-beds, low-energy areas, were Caecum comu- 
copiae Carpenter (Figs. 13 and 14) and C. mtidum 
Stimpson. Distinguishing between these two 
species is rather difficult, but C. nitidum tends 
to be larger with a more oblique aperture in the 
adult stage. The row of dark spots sometimes 
seen on C. comucopiae by Moore (1972) was not 
apparent in the specimens from the grassbeds 
and only seen on two specimens from a reef area 
in a southside bay. In the reef, or medium wave- 
energy areas, the most abundant species was 
C. regulare Carpenter (Figs. 25, 26, 27 and 28). 
C. breve Folin (Figs. 1 and 2), C. lineicinctum 
Folin (Figs. 31 and 32), and C. floHdanvm Stimp- 
son (Figs. 19 and 20) were also found in these 
areas. The dominant species in the rocky, high 
wave-energy areas on the southern side of the 



island was C. imbricatum Carpenter (Figs. 3 and 
4). A rare species, C. tenuicostatum Folin (Figs. 
5, 6, 7, 8, 23 and 24) was also found in these 
areas. Some of the specimens of C. tenuicostatum 
appear under the SEM to have longitudinal ribs 
which are smoother and less raised on one side, 
giving an appearance of wavelike ribs moving 
clockwise looking down from the aperture. 

One species common to all areas is C. textile 
Folin (Figs. 11 and 12). Some specimens of C. 
textile (Figs. 17 and 18) appear under the light 
microsc-ope as having a raised interspace between 
the annular ridges, giving an almost smooth ap- 
pearance, while the SEM reveals that the longitu- 
dinal striae on the ridges are continued through 
the interspace and are joined to those on the 
adjacent ridges (Fig. 18). Another species, also 
common to all wave-energ>' environments, is C. 
regulare Carpenter and its close relative, C. 
gurgulio Carpenter (Figs. 15 and 16). The sculp- 
ture of C. regulare, as revealed by the SEM, 
shows an absence of striae between the well- 
raised, flat-topped annular ridges (Fig. 26). This 
can also be seen in the specimen described by 




FIC.S. 17-24. 17, C. textile Fo/i« X.W, 18, C. textile /-"o/ih X^IO; 
19, C. floridanum Stimiison X20: 20, C. floridanum Stimpsmt 
X1J,'>: 21, C. (iimnicKirei h.s. jximlinx' XW: 22, C. donmoorei 
n.x. iximtifiH' X1.',(K 23, ('. tenuicxistatum FuUn Second xtage 
XJO: 24, C. tenuicostatum Falin X«ft 



V(,1.9H(2-:?) 



April 23, 1979 



THE NAUTILUS 105 




FIGS. 25-:32. 25, C. regulare Cm-pent er XIO; 26, C. regulare 
Carpetiter X210: 27, C. regulare Carpenter Second staye plus 
part of third staye XJS: 28, C. regulare Carpenter X175: 
29, C. donirnwrei n.s. Imlotyije X20: 30, C. donmoorei n.s. ho- 
kitifiw Xl'O; 31, C. lineicinctum Folin X20: 32, C. linei- 
cinctum Folin XSO. 

Moore (1972). C. gurgulio is very similar in ap- 
pearance, but is smaller, has less curvature, and 
low, flat-topped, closely set ribbing with striae 
present only between the ribs (Fig. 16). 

Caecum donmoorei, n. sp. 

DescriTption: Shell tapered with slight curva- 
ture; 27 annular ribs well-spaced, raised, 
rounded-topped (Fig. 31); primary striae in inter- 
space thick; secondary striae thin; all striae con- 
tinue over surface of ribs (Fig. 32); Septum 
slightly convex, bearing broad, weak mucro 
angled to right; two small circular ribs around 
circular aperture; no varix; color white in holo- 
type, some specimens tinged brovm near aper- 
ture; length 1.4 mm. 

Remarks: This species has round-topped and 
striated ribs as opposed to the smooth, flat -topped 
ribs of C. regulare. It differs from C. giuyulio 
which has rounded, robust, but not so raised, ribs 



which are small, smooth, and bear no striae. 
There is also no similarity to C. toniatum Verrill 
and Bush which has strong ribs and a very strong 
mucro and appears to be confined to Bermuda. 
The most distinguishing feature of C. donmoorei 
which appears to justify the naming of a new 
species, is the round-topped striae-covered ribs. 
This species is named after Dr. D. R. Moore, a 
leader in the field of the study of the Caecidae. 

Tijpe -locality: Holotype: In 5 m of water in 
Sprat Bay, Water Island, USVI. Four paratypes 
were found in Ruyter Bay and Elephant Bay at 
similar water depths and of low wave-energy. 

Ti/pen: Holotype deposited in 1977 in the Dela- 
ware Museum of Natural History #119521. Para- 
types were placed in the collection at the Florida 
Bureau of Geology, Tallahassee, #12909. 

ACKNOWLEDGMENTS 

I am grateful directly to Dr. J. R. Taylor for 
allowing the examination of the collection held at 
the British Museum of Natural History in Lon- 
don, and indirectly to Dr. D. R. Moore for his 
work of classifying some of this collection. I am 
also grateful to Philip Dawson of St. Thomas for 
his aid in the collection of the samples, and to 
Dr. S. W. Wise and Dr. R. Wright of the Depart- 
ment of Geology of The Florida State University, 
Tallahassee, and Dr. D. R. Moore, University of 
Miami, Miami, for their reading and criticism of 
the manuscript. Scanning electron micrographs 
were taken on an ISI Supermini I, housed in the 
Department of Geology at The Florida State 
University. Support in part was provided by NSF 
grant #121-323-210. 

LITERATURE CITED 

Moore, D. R. 1969. A new Caecum from the tropical Western 
Atlantic. TheNautilm 83(l):26-28. 

. 1970. A new Caecum from Puerto Rico and the Vir- 
gin Islands. Bull. Mar. Sn. 20(2):368-373. 

. 1972. Ecological and systematic notes on Caecidae 

from St. Croix. U. S. Virgin Islands. Buil. Mar. Sci. 22(4): 
881-899. 

Weber, J. A. 1961. Marine shells of Water Island, Virgin Is. 
The Nautilus 75(2):55-60. 



106 THE NAUTILUS 



April 23. 1979 



Vol. 93 (2-3) 



DISCOVERY OF LIVING BIVALVED GASTROPODS IN THE FLORIDA KEYS 



Donald R. Moore 

University of Miami Rosenstiel School of 

Marine and Atmosphere Science 

Miami, Florida 33149 



Mabel Fentress Miller 

and Environmental Education Propram, 

Science Education Dept. 

Dade County Public Schools 

1410 Northeast Second Avenue 

Miami, Florida 33132 



The first living bivalved gastropod was observed 
by Kawaguti just twenty years ago (Kawaguti 
and Baba, 1959). A year later, in October 1900, 
Kawaguti visited Miami in an effort to find these 
animals in the western Atlantic. He was unsuc- 
cessful, but shortly after Edmunds (1962) re- 
ported a species from Jamaica. This species was 
described as Berthelinia caribbea Edmunds, 1963. 
B. canbbea was reported from Puerto Rico by 
Warmke (1966), and later from Panama and 
Brazil (Meeder and Moore, 1972). 

The search for B. caribbea in United States 
waters was unsuccessful for many years; then 
one of us (MFM) collected eight live specimens in 
the Florida Keys on 14 July 1978. They were 
collected in sea wall scrapings from a canal off 
Tavernier Creek, Plantation Key. After being 
observed alive, they were preserved in alcohol. 
Four of these were donated to the School of Marine 
Science, University of Miami. 

This is the first living species of the family 
Juliidae to be reported from Florida. A fossil 
species, Julia Jloridana Dall, 1898, was described 
(as a pelecypod) from the Oligocene of north- 
western Florida along the Chipola River. The 
genus Julia is presently found living in the cen- 



tral and western Indo-Pacific, and is known from 
two fossil species in the western Atlantic area. 
Berthelinia caribbea is not likely to be found as 
a fossil, however, as it is extremely thin-shelled. 

B. caribbea is now known from the Florida 
Keys, Jamaica, Puerto Rico. Panama, and Brazil. 
It appears to have plankton ic larvae, and should 
be found at many more localities in the Tropical 
Atlantic. 

LITERATURE CITED 

Dall. W. H. 1898. Contributions to the Tertiary fauna of Flor- 
ida. Trans. Wagner Free Inst. Sci. Philad. 3(4):.571-947. 
pis. 23-.i5. 

Edmunds. M. 1962. Bivalve gastropod from .Jamaica. Nature, 
195:402. 

. 196.3. Berthelima raribben n. sp.. a bivalved gas- 
tropod from the west Atlantic. .1. Linn. Soc. London 
44(9)2): 7.31 -7.39, pi. 1. 

Kawaguti. S. and K. Baba. 19.59. A preliminary note on a two- 
valved sacoglossan gastropod. Tamanuvalva limar. n. gen., 
n. sp., from Tamano. .Japan. Biol. .J. Okayama Univ. 6(3-4): 
177-184. 10 figs. 

Meeder. .1. F. and D. R. Moore. 1972. The extension of range of 
RcrthrUiua mnhhea Edmunds to Brazil and Panama (Mol- 
lusca. (lastropoda). Carib. Jmir. Sci. 11(3-4):1.")9-161. 

Warmke. G. 1966. Two species of the bivalved gastropod Berthe- 
linia found in Puerto Rico. The Nautilus 79(4):1.39-141. 



This issue of \'ol. 9:^ cnnibines numbers 2 and 3. Numbei- 1 will h' published in October. 1979. 



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Museum of Comparative Zoology 
Cambridge, Mass. 02138 

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The American Museum of Natural History 
New York, New York 10024 

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Department of Living Invertebrates 
The American Museum of Natural History 
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The Ohio State University 
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Los Angeles County Museum of Natural History 
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School of Marine and Atmospheric Science 
10 Rickenbacker Causeway 
Miami, Florida 33149 

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U. S. National Museum 
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THE 

NAUTILUS 

Volume 94, number 4 — October 30, 1979 

ISSN0028-1344 



CONTENTS 



Donald M. Allen 

Bioldgical aspects of the Calico Scallop. Argopecten Gibbu.% determined by Spat Monitoring 107 

Francis R. Home and Steve Mcintosh 

Factors influencingdistribution of Mussels in the Blanco Riverof Central Texas 119 

Miguel A. Klappenbach 

Allocation of "Mnryinclln "Cordrroi Carcelles, 1953 to a New Genus in the 

Volute Subfamily Odontocymbiolinae (Gastropoda) 133 

Alex S. Tompa 

Localized egg shell dissolution during development in Stenotrema Leai 

(Pulmonata: Polygyridae) 136 

Arthur H. Clarke 

Gastropods as indicators of Trophic Lake Stages 138 

Leslie Hubricht 

A New Species of Amwico/a from an Arkansas Cave (Hydrobiidaoe) 142 

K. Elaine Hoagland 

The Behavior of Three Sympatric Species of Orpiduln 

(Gastropoda: Pi'osobranchia) from the Atlantic, with implications for Evolutionary Ecology .... 143 
John J. Jenkinson 

Tlie Occurrence and Spread of Corbicula Manilensis in East -Central Alabama 149 

Archie L. Jones 

Descriptionsof Six New Forms of Florida Tree Snails, LM7?iusFa.sCTa<2i.s 153 

R. Tucker Abbott and C. John Finlay 

Oiicdrnii^ Gismnni. a New Muricid Gastropod from the West Indies 159 

Susan B. Gallagher and George K. Reid 

Population Dynamics and Zonation in the Periwinkle Snail, Littorina Angulfera. 

of the Tampa Bay, Florida, Region 162 

Arthur H. Clarke 

Sphaeriidae as indicators of Trophic Lake Stages 178 

A. Omura. W. K. Emerson and T. L. Ku 

Uranium - Series Ages of Echinoids and C«rals from the Upper Pleistocene 

Magdalena Terrace, Baja California Sur, Mexico 184 

Walter E. Klippel and Paul W. Parmalee 

The Naiad Fauna of Lake Springfield, Illinois: an Assessment after Two Decades 189 

Publications Received ii 



PUBLICATIONS RECEIVED 



Leathern. Wayne and Don Maurer. 1979. (Revised edition of) 
Phylum Mollusca: A Guide to the Mollusca of Delaware 
Bay Region. 42 mimeographed pp. A key to the known 
species. $3.00. Publications, C.M.S., Univ. Delaware. Newark, 
DE 19711. 

Gibson-Smith. J. and W. 1979. The Genus Arcinella (Mollusca: 
Bivalvia) in Venezuela and Some Associated Faunas. Geos 
no. 24: 11-32, 3 pis. A. jungi and A. candelariana n. spp.. 
and Nicotia n. subgenus (type: Chama draconis Dall) from 
the Miocene are described. Purpura weisbordi n. sp. is what 
Weisbord. 1962. called P. patula Linnaeus. Many of 
Weisbird'.s 1962 species are sv-nonymized. 

Menzel, R. W. 1974. Portuguese and Japanese Oysters are the 
Same Species. Jour. Fish Research Bd. Canada 31(4): 
45:3-456. The author suggests, on biological evidence, that 
Crassostrea angidata Lamarck (1819) from Portugal be con- 
sidered a subspecies of C. gigas (Thunberg. 1793) from 
Japan, the latter possibly having been introduced from Por- 
tugal. 

Purchon, R. D. 1978. An Analytical Approach to a Classifica- 
tion of the Bivalvia. Phil. Trans. Royal Soc. London. B. 284: 
425-4.36. 

/( Naturalkla Siciliano. vol. 1 and 2 (1977-78). A new quarter- 
ly containing several scientific papers on mollusks. Instituto 
di Zool. della Univ., 18 Via Archirafi, Palermo, Italy 90123. 

Eyster. Linda S. 1979. Reproduction and Developmental 
Variability in the Opisthobranch, Tenellia pallida. Marine 
Biology, vol. 51, pp. 1,3;V140. Pelagic and non-pelagic develop- 
ment occurs within single population. 

Ti-yonia, no. 1. Catalog of the Chiton T>T)es of the Academy of 
Natural Sciences of Philadelphia. By G. M. Davis. R. 
Robertson and M. Miller. .56 pp., mimeographed. .$7.00. 
Miscellaneous publication of the Dept. Malacology-, Acad. 
Nat. Sci. Phila.. Phila.. PA 19103. Lists primary t.vpes and 
syntypes. with complete data, and by geographical areas. 

Jaume, Miguel L. and Alfredo de la Torre. 1976. Los Urocop- 
tidae de Cuba (Mollu.sca - Pulmonata). Cieticias Biological 
(Habana). no. .53, 122 pp. Contains numerous new genera 
and specie.s. Originally published in Circulares del Museo y 
Biblm. Zool. Habana, 1972. pp. 1.526-1649. 

Davis, George M. 1979. The Origin and Evolution of the 
Gastropod Family Pomatiopsidae, with Emphasis on the 
Mekong River Triculinae. Monograph 20. Acad. Nat. Sci. 
Philiulclphia. 120 pp. An extensive zoogeographic and 
phylogenetic review, with two new genera. The author 
employs the u.se of Triljes and erects two new names under 
the subfamily Triculinae. 

Gate, Crawford N. 1979. A Review of the Tiiviidae. Memoir 
10, San Diego Society of Naiural Histoi-y. 126 pp., 177 figs. 
An extensive review, with five new genera and 40 new 
species. 

Zhuang. Qi-qian. 1978. Studies on the Mesodesmatidae 
(Lamellibranchia) off the Chinese Coast. Studia Marina 
Sinira. vol. 14. no. 14, pp. 69-74, 1 pi. Treats with Atactodea, 
Darila Oiccclla and Anapelta retrocunvexa n. sp. from 
N;ur/,how Island, China. 



Pidmonates. Vol. 2 A, Systematics. Evolution and Ecology 
(edited by V. Fretter and J. Peake). .540 pp. Academic Press, 
London, N. Y. 1979. $50.75. 10 chapters of varying contents 
and quality, some outstanding on systematics. distribution, 
classification, natural selection and ecology by fourteen 
well-known malacologists. 

Pulmonates. Vol. 2 B, Economic Malacolugy u-ith particular 
reference to Achaiina fulica. by A. R. Mead. 1.50 pp. 
Academic Press, London, N. Y. 1979. $2,520. This is an up- 
date and condensed version of Dr. Mead's 1961 "The Giant 
African Snail" ($8.00). A previous book. Medical and 
Economic Malacology, by Malek and Cheng, published by 
Academic Press in 1974, covers the economic field more 
broadly and adequately. 




FORTHCOMING BOOK 
SEA SHELLS OF WESTERN EUROPE 

by Philippe Bouchet 
Photography by F. Danrigal and C. Huyghens 

An exquisite little guide to the habits, 
life histoiT and identification of the com- 
mon moUuskes of Western Europe. 142 
spectacular, colored photographs of egg- 
laying, breeding, and reproducing, as well 
as very colorful, close-up views of snails, 
nudibranchs, clams and squids. Also con- 
tains 11 plates of identification figures. One 
of the loveliest of the new generation of 
shell books. Hardback. 144 pp. $8.95. 
Published by 

American Malacologists, Inc. 

P.O. Box 2255 
Melbourne, FL .32901 USA 



Vol.94 (1) 



October 30, 1979 



THE NAUTILUS 107 



BIOLOGICAL ASPECTS OF 

THE CALICO SCALLOP, ARGOPECTEN GIBBUS, 

DETERMINED BY SPAT MONITORING' 



Donald M. Allen 

NOAA, National Marine Fisheries Service 

S(iutheast Fisheries Center 

Miami, Florida 33149 

ABSTRACT 

Biological information on the calico scallop. Argopecten gibbus, was collected 
using spat traps as monitoring devices on the Cape Canaveral grounds off the 
Florida east coast from March 1970 to October 1971. The shells of noung scallops 
(spat) differ in shape and color from those of adult scallops. Spat and, by deduc- 
tion, the larval scallop.% occurred at five sampling locations off Cape Canaveral in 
depths of 9 to 2Jf m; spat were most abundant at the 18 m site. There was no 
evidence that scallop larvae survived in estuarine waters in the Cape Canaveral 
area. Based on spat distribution, la}-vae were apparently distributed throughout 
the water column but were least abundant near the surface. Seasonally, spat were 
most abundant in the spring. Growth estimates .show that young scallops can reach 
1.5 m,m shell height in 1 month from spawning, 17.0 mm in 2 months, and 28.0 mm 
in 3 months. Setting apparently occun-ed at a minimum size of 0.25 mm shell 
height and apnt showed strong byssal attachment up to at least 5.0 or 6.0 mm shell 
height. Spat may utilize filamentous host organisms, such as hydroids. for setting, 
perhaps before attaehment to shell. Numerous inveHebrates were associated with 
calico .scallops in the traps, but calico scallops ivere generally dominant. 

Based on spat abundance, spawning of adults occurred during all seasons, but 
intensity was highest in spring (March through May) when bottom water 
temperatures associated unth spauming scallops were probably about 18°C. 

Recommendations for future spat monitoring are discussed. 



The calico scallop, Argopecten gibbus, supports 
a small fishery off the southeastern United 
States. The scallop grounds are located off North 
Carolina, off the Florida east coast, and in the 
northeastern Gulf of Mexico (Figure 1). Abun- 
dance and distribution of scallops on the grounds 
are seasonally and annually variable, which has, 
in part, contributed to the slow development of 
the fishery. To recognize factors controlling the 
abundance and distribution of the calico scallop, 
the Bureau of Commercial Fisheries (now the Na- 
tional Marine Fisheries Service), Miami, Florida, 
conducted laboratory and field studies of the 
biology of this species from 1969 to 1971. 

Biological information concerning certain 



' Contribution Number 79-37M, NOAA, National Marine 
Fisheries Service, Southeast Fisheries Center. Miami, FL 
33149. 



marine invertebrates has been revealed by their 
habit of attaching to or "fouling" of submerged 
objects (Woods Hole Oceanographic Institution, 
1952; Merrill, 1965). Artificial substrates, such as 
test surfaces or fouling panels, are used in 
biological monitoring because of the relative ease 
with which the unit of sampling effort can be 
standardized and controlled (Calder and 
Brehmer, 1967; Cory, 1967; Pequegnat and Pe- 
quegnat, 1968). Spat collecting devices, made of 
oyster shells or asbestos plates, are particularly 
useful in oyster biological studies that have 
direct application to the commercial fishery 
(Loosanoff, 1966; Shaw, 1967). 

Scallops (family Pectinidae) attach to 
substrates by means of byssal threads. The first 
byssal attachment of young scallops after a 
planktonic existence is called "setting," and the 



108 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 




FIG. 1. G( ncnil dixlribtituin af the calicu scattop and primary 
scallop fishing grtmnds. (Modified fi^om Cummins, 1971: A Hen 
and Oistello. 1972). 

recently set scallops are called "spat." Setting 
was described for the bay scallop, Pecten irra- 
diaiK (now Atyopecteti irmdians), by Belding 
(1910). Young scallops of various species will set 
on natural and artificial substrates (Belding, 
1910; Woods Hole Oceanographic Institution, 
1952; Merrill, 1965; Brown et al., 1967; Dow, 
1969; Costlow, 1969; DePalma, 1969; Turner, 
Egbert, and Given, 1969 and Golikov and Scarlato, 
1970.) Under natural conditions, calico scallop 
spat are generally found attached to mollusk 
shells, primarily the empty valves of calico 
scallops (Allen and Costello, 1972). Calico scallop 
spat have also attached to navigation buoys 
(Waller, 1969) and plastic peanut floats (Pe- 
quegnat, Gaille, and Pequegnat, 1967). 

The setting habits of scallops suggested that 
calico scallop spat might be effectively sampled 
using artificial substrates as collecting devices. 
An effective spat collector, briefly described by 
Allen and Costello (1972), was developed by me in 
early 1970. Later spat monitoring, using this 
device, provided basic data concerning spat: 
description, distribution and abundance, age and 
growth, behavior, and associated organisms; and 
spawning of adults. In recent years, a similar 
spat collecting device has been used in a Japanese 
commercial scallop culture system (Dix, 1977). 
METHODS 

In preliminary field tests off Cape Canaveral, 
Florida (Figure 2), young calico scallops byssally 
attached to a variety to cultch materials in addi- 



tion to calico scallop shells. Unlaid polyethylene 
line, which forms a filamentous tangle, was par- 
ticularly effective as cultch. Comparison of cultch 
effectiveness was difficult because many of the 
larger spat dropped from the cultch as it was 
removed from the ocean. To minimize the loss of 
spat that may release attachment before or dur- 
ing the time spat collectors were retrieved, the 
cultch was contained within wire plastic or 
nylon mesh of appropriate size. 

The standardized spat collector (designated 
"spat trap") used during most of this study con- 
sisted of a small, nylon mesh bag stuffed with a 
fixed quantity of unlaid polyethylene line (Figure 
3). The nylon bag was 56.0 cm long and 30.5 cm 
wide, with mesh openings about 3.0 mm in 
diameter. Polyethylene line, diameter 9.4 mm and 
length 61.2 cm, was separated into individual 
filaments and placed in the bag, along with a 
plastic identification label. The bag was closed by 
means of a figure-eight knot tied in the bag at its 
midpoint. Excess bag material was drawTi down 
over the knot and tied with nylon parachute 
cord, which also secured the spat trap to a ver- 
tical line at a selected position in the water col- 
umn. These spat traps survived well in the 
marine environment, because their components 
did not decompose rapidly. 

The spat traps filtered large quantities of 
water from currents which presumably carried 
the scallop larvae to the traps where the larvae 
set and grew. Young scallops inside the traps 
were permanently trapped when their size ex- 
ceeded the 3.0 mm mesh openings. Probably few 
spat less than 3.0 mm shell height^ were lost 
during recovery of the traps because spat in this 
size category show strong byssal attachment. 

Preliminary comparative studies indicate that 
standard spat traps containing 61.2 cm of unlaid 
line caught more spat than mesh bags containing 
no line but stretched with wire to a size and 
shape similar to that of the standard traps. When 
the amount of line in the traps was increased to 
183.6 cm, the numbers of spat caught increased, 
but their growth declined markedly. Further- 
more, the tightly packed line apparently caused a 
high incidence of deformed valves and mortality 
among the larger spat. As noted by Merrill and 

' Shell heipht is a straight measurement of the greatest 
distance between the umbo and the ventral margin. 



Vol. 91 (4) 



October 30, 1979 



THE NAUTILUS 109 




■■■ \ 

F 


yV luo't I •"<>' 2 




vXv '^ 


) 


\ 1 1 Jy^*''^ CANAVERAL 


i 1 ) \.^t, ifOilCiMVtlU 



A MONITORING SITES 



- <y.'' 



81 



-r 



— r- 

79" 



78' 



-r 



FIG. 2. Calif (J ^calhip tspat mimitnring siten nff Cape 
Caiuiveral and geographic locations along the eiixt count of 
Florida, 

Edwards (1975) for young sea scallops, 
Placopecten magellanicus. growing in fouling 
communities, "The mantle is apparently easily 
injured, and evidence of serious shell malforma- 
tion was seen in situations where other 
organisms were in close approximation to the 
scallop." In the standard spat traps, no defor- 
mities occurred. Extensive mortality did occur in 
standard traps that were exposed for almost 4 
months, but the causes are unknovm. These traps 
contained potential predators (including starfish, 
crabs, and gastropod mollusks) and competitors 
(bivalve mollusks) that had apparently passed 
through the meshes as larvae and were 
themselves trapped. In addition, the meshes were 
clogged with silt. 

Five sites to monitor calico scallop spat 
distribution and abundance were established off 
the Florida east coast near Cape Canaveral, in 
depths of 9 to 24 m (Table 1, Figure 2). U.S. Coast 
Guard navigation buoys or special service buoys 
marked each site and enabled location and 
recovery of the spat traps after exposure for ex- 
tended periods of time. It was necessary to 
establish the sites inshore of the greatest adult 
scallop concentrations because of the absence of 
large, permanent buoys in the offshore waters. 



Adult scallops occurred near Buoys 1 and 2 but 
were rare or absent at the remaining three sites. 

In use, the spat traps were attached to a spat 
monitoring array that was typically composed of 
an anchor, vertical line, stabilizing float and sur- 
face buoy. To facilitate recovery, the arrays were 
positioned within sight of the permanent buoy at 
each site. In some areas, where danger of propeller 
cutoff and theft was great, the surface buoy was 
retained underwater until released by a timed 
magnesium fuse shortly before scheduled recovery. 
For most of the comparative studies, two spat traps 
were located on the vertical line at positions 0.6 m 
and 6.0 m above the ocean bottom. For special pur- 
poses, additional traps were located 0.9 m below the 
water surface and elsewhere in the water column. 

The preliminary, experimental spat collecting 
devices were first set out in March 1970. After 
refining techniques, standardized spat traps, 
useful for comparing abundance, were exposed for 
varying periods of time from July 1970 to Oc- 
tober 1971. Scallops caught by both the 
preliminary and standardized traps were used in 
the growth study. The shortest exposure time was 
11 days, and the longest, 117 days. Losses of ar- 
rays were common and were attributed to strong 
currents, entanglement with fishing gear, theft, 
and propeller cut-off. Most of the successful 
recoveries of arrays were at Buoys 1 and 2, the 
sites most remote from vessel traffic or fishing 
activities. 

When the spat traps were recovered from the 
ocean, they were placed in fine-mesh nylon bags 
(mesh size about 0.75 mm) and preserved in 10% 
Formalin.' Although the spat apparently released 
byssal attachment upon contact with Formalin, 
the fine-mesh preserving bags retained spat as 
small as 0.75 mm shell height and helped main- 
tain the integrity of each spat trap during the 
later flushing, freezing (for preservation), and 
thawing process. 

The calico scallop spat (including empty shells) 
and associated organisms from each spat trap 
were sorted and counted. An unknowm number of 
very small spat (less than 0.75 mm shell height) 
may have been washed through the fine-mesh 
preserving bag or overlooked by the sorters. 
Other species of scallops were caught in the traps 



' Reference to trade names does not imply endorsement by 
the National Marine Fisheries Service, NOAA. 



110 THE NAUTILUS 



October 30. 1979 



Vol. 94 (4) 



but constituted less than 1% of those larpe 
enough to be identified to species. The scallop 
spat were measured for shell height. Spat less 
than 1.0 mm shell height were measured to the 
nearest 0.25 mm, those from 1.0 to 5.0 mm to the 
nearest 0.5 mm, and those more than 5.0 mm to 
the nearest 1.0 mm. Scallops from 0.25 to 27.0 
mm shell height were found in the trap samples. 
One trap, exposed for 35 days, contained 4,761 
spat that ranged from 0.75 to 8.0 mm shell height. 

Since the "catching effort" of the spat traps 
varied with exposure time, catch data were stan- 
dardized by calculating the average number of 
spat caught per trap per day of exposure. 

Thermographs recorded bottom temperatures 
at Buoys 1 and 2 during most of the study period, 
but there were intervals when no data were col- 
lected because of thermograph malfunction or 
loss. 

Spat 

Description 

The calico scallop shell was described by 
Waller (1969). Shells of calico scallop spat col- 
lected in spat traps on the Cape Canaveral 
grounds (Figure 4) differed in shape and color 
from shells of adult scallops collected in the same 
area. 

Shell height was usually greater than shell 
length" in .spat 1.0 to 8.0 mm height. At about 
9.0 mm shell height, shell length began to in- 
crease more rapidly than shell height, and from 
my additional observations of larger scallops, and 
those of Wells, Wells, and Gray (1964), this rela- 
tionship apparently continued throughout life. In 

Table 1. Locations aod depths of calico scallop spat monitoring sites 
off Cape Canaveral, Florida. 





Latitude 












and 




Distance 




Buoy 


longitude 


trom land 


Depth 










don) 


(m) 


Buoy 1 


m" 


48.5^ 


N 


9 


18 




»u° 


38. b 


W 






Buoy 2 


28° 


49. l] 


H 


22 


22 




80° 


29.0 


U 






Heczel Shoal 


28° 


38.2! 


N 


22 


24 


Buoy 


8U° 


21.0 


U 






Port C«Dsveral 


28° 


22.9! 


N 


U 


17 


R2 Buoy 


80° 


25.5 


U 






Port Caooveral 


28° 


23.8; 


N 


6 


9 


RUlt6 Buoy 


80° 


32.2 


V 








FIG. 3. Spat trap, cmutisting nf nylon mesh bag (top) and 
unlaid palyethylene line (bottom right). Calico acallap spat 
(center) exceed mesh openings in size. (Prom Allen and 
Costello. 19721. 

trawl-caught scallops, shell length did not begin 
to increase more rapidly than shell height until a 
shell height of about 30.0 mm was reached. 

Length of the hinge line was about equal to 
shell length in spat 1.0 to 1.5 mm shell height. 
However, as shell height increased, hinge line 
length increased more slowly, so that at 8.0 mm 
shell height (approximately 8.0 mm shell length) 
hinge line length was 6.0 mm. 

Spat less than about 10.0 mm shell height were 
noticeably compressed, or flattened, as compared 
with the strongly inflated adult scallops. For spat 
ranging from 3.5 to 8.0 mm shell height, depth'^ 
was only about 27 to 31% of shell height. As shell 
height increased, depth increased disproportion- 
ately. For spat 19.0 to 23.0 mm .shell height, 
depth was about 37 to 46% of shell height, and 
for scallops 37.0 to 65.0 mm shell height (caught 
by bottom trawl), depth was about 54 to 64% of 
shell height. 

There was a difference in convexity* between 
the left (upper) and right (lower) valves in spat 
from 1.5 mm up to at least 8.0 mm shell height. 
For spat 3.5 to 4.5 mm shell height, the left valve. 



' Shell length i.s a straight line mea.-iurement of the greatest 
distance between the anterior and posterior margins. 



' Depth is the sum of the convexities (see footnote (i) of the 

left and right valves. 

' Conve.xity is the maximum distance lietween the exterior 
surface of a v.dve and the measuring platfunn. me;usured 
along a line perpendicular to the measuring platform (Waller, 



V(,1.91 (1) 



October 30, 1979 



THE NAUTILUS 111 




FIG. 4. Calico scallop spat from 2.5 to 16.0 mm shell 
valve in on bottom. 

strongly convex, accounted for 65 to 81% of the 
depth, while the right valve, weakly convex, ac- 
counted for only 18 to 34% of the depth. Convexi- 
ty of the valves became more equal as shell 
height increased. Waller (1969), apparently 
discussing adult scallops, observed that the valves 
were "generally equiconvex to slightly left con- 
vex." 

Spat ranging from 0.75 to 18.0 mm shell height 
had white, tan, violet, brovm, red-brown, and 
orange-brown valves. Some mottling or banding 
occurred on spat as small as 2.0 mm shell height. 
Colors on the left valve were darker than those 
on the right valve, which was generally white or 
light tan. Colors on the left valve became darker 
and more intense as size increased. White and 
tan were common base colors on the left valve of 
spat 0.75 to 8.0 mm shell height, grading into 
brown and red-brown as size increased up to 18.0 
mm shell height. 

A fairly common characteristic of spat, par- 
ticularly those from about 4.0 to 8.0 mm shell 
height, was a white streak bisecting the left 



height. For e<wh pair, kjt rale 



lilt top and right 



valve, extending from near the umbo to the ven- 
tral margin and encompassing the width of a few 
ribs. 

LHstribution and Abundance 

The general distribution of the calico scallop 
was summarized from several sources by Allen 
and Costello (1972), who stated that the range of 
this species ". . . extends from the northern side 
of the Greater Antilles and throughout the Gulf 
of Mexico to Bennuda and slightly north of Cape 
Hatteras." According to Allen and Costello (1972), 
"The greatest known abundance is located off the 
Florida east coast near Cape Kennedy [Cape 
Canaveral], with lesser concentrations near Cape 
Lookout, N. C, and in the northeastern Gulf of 
Mexico near Cape San Bias, Fla." Sporadic com- 
mercial concentrations also have been reported 
off Savannah, Georgia, and along the west coast 
of Florida, from off Egmont Key to Key West 
(Figure 1). 

Although the calico scallop may consist of one 
population throughout its range, with planktonic 
larvae from stock in one area contributing to 



112 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



stock in another area, there is little evidence to 
suprK)rt this theory. Oceanic currents probably 
determine the direction of transport of the lan'ae 
(Waller, 1969). Therefore, the Gulf Stream 
system, and associated countercurrents, may be 
important in larval distribution. Kirby-Smith 
(1970) suggested that part of the North Carolina 
calico scallop stock may result from larvae 
transported northward from the Cape Canaveral 
grounds by the Gulf Stream. The origin of the 
calico scallops on the Cape Canaveral grounds is 
unknown. These scallops may be either self- 
sustaining or partially dependent upon larvae 
transported from more distant spawning stocks, 
presumably (but not necessarily) located farther 
south than the lower end of the Cape Canaveral 
grounds near Stuart, Florida. Calico scallops oc- 
cur in the Florida Keys (Waller, 1969), and these 
scallops may supply larvae to the Cape Canaveral 
grounds (Figure 2). This hypothesis, however, 
does not negate the fact that there is a large 
stock of spawning scallops on the Cape Canaveral 
grounds, and water circulation in the Cape 
Canaveral area might be expected to retain 



scallop larvae on the grounds until setting occurs, 
since surface currents off Cape Canaveral reverse 
direction to north or south with wind changes, 
and bottom currents converge toward the cape 
from offshore (Bumpus, 1973). 

Calico scallop spat were caught in traps at all 
five study sites off Cape Canaveral (Table 2). This 
might be e.xpected since the wide distribution of 
adult scallops on the Cape Canaveral grounds 
(Drummond, 1969) would presumably contribute 
to the wade distribution of larvae in this area. 
The intensity of spat setting (or survival) be- 
tween sites was variable. Where mmparisons be- 
tween sites could be made, they showed spat to 
be most abundant, generally, at Buoy 1 and least 
abundant at Port Canaveral RWR6 Buoy. For ex- 
ample, traps exposed from May 25 to June 26, 
1971 (35 days) caught 2,320 spat at Buoy 1 (9 km 
offshore, 18 m of water), 895 spat at Buoy 2 (22 
km offshore, 22 m), and 21 spat at Port Canaveral 
RWR6 Buoy (6 km offehore, 9 m) (Table 2). 
Variability in setting between locations was also 
observed in the northeastern Gulf of Mexico, 
where calico scallop spat attached to biofouling 



Table 2. Seasonal abundance of calico scallop spat at monitoring sites oft Cape Canaveral, Florida, July 1970 to October 1971. 



Spat Trap hxposure 


Buoy 1 


Buoy 1 


Hetzel 

Total 


Shoal Buoy 
Per day 


Port Canaveral 
R2 Buoy 


Port Canaveral 
RWR6 Buoy 


Period Daya 


Total Per day 


Total Per day 


Total Per day 


Total Per day 



7/21/70 
8/26/70 
11/11/70 
1/06/71 
1/06/71 
1/24/71 
1/24/71 
2/16/71 
3/16/71 
3/16/71 
4/01/71 
4/20/71 
5/25/71 
6/26/71 
8/24/71 



8/26/7U 
11/11/70 
1/24/71 
1/24/71 
2/16/71 
2/16/71 
3/16/71 
3/16/71 
4/01/71 
4/20/71 
4/12/71 
5/25/71 
6/26/71 
8/24/71 
10/27/71 



35 
76 
74 
18 
41 
23 
51 
27 
16 
35 
11 
35 
32 
59 
64 



227 6.5 

39 0.5 

134 1.8 139 1.9 



4,562 130.3 1,531 43.7 

2,300 65.7 1,181 33.7 

2,320 72.5 895 28.9 

142 2.4 536 9.1 

21 0.3 70 1.1 



-number of spat per trap 



60 


3.3 


384 


9.4 


361 


15.7 


35 


1.3 


1 


0. 1 



1 Spat size ranged from 0.23 to 27.0 mm shell height. 

2 Spat traps were positioned about 0.6 m above ocean floor. 

3 Dashes Indicate no data (i.e., trap was not exposed, or if exposed, not recovered). 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 113 



Table 3. Vertical distribution of calico scallop spat at monitoring sites off Cape Canaveral, 
Florida, November 19/U to October 1971. 









Buoy 1 








Buoy 2 




Spat trap e 


xposure 
















period 


Surface 


Intermediate 


Bottom 


Surface 


Intermediate 


Bottom 


11/11/7U - 


1/24/71 


__1 


1.2 


-numb 


er of spat 
1.8 


per trap 


per day 

2.2 


1.9 


1/24/71 - 


3/16/71 


— 


1.0 




13.6 


~ 


0.7 


3.7 


3/16/71 - 


4/20/71 


— 


110.5 




130.3 


~ 


44.4 


43.7 


4/20/71 - 


5/25/71 


0.5 


136.0 




65.7 


0.3 


75.9 


33.7 


5/25/71 - 


6/26/71 


— 


41.7 




72.5 


~ 


26.5 


28.9 


6/26/71 - 


8/24/71 


— 


2.2 




2.4 


~ 


15.2 


9.1 


8/24/71 - 


10/27/71 


~ 


1.3 




0.3 


~ 


1.2 


1. 1 



1 Dashes indicate no data. 

Note: Surface traps were positioned about 0.9 m 
above ocean floor, and bottom traps 0.6 m 

arrays more abundantly at sites 19 km offshore 
than at sites 4 or 41 km offehore (Pequegnat and 
Pequegnat, 1968). 

The usual distribution of adult calico scallops 
indicates that the larvae are restricted to open 
marine water. The larvae, however, sometimes 
enter estuarine waters, based on reported oc- 
currences in semi-enclosed sounds of juveniles in 
North Carolina (Waller, 1969) and adults in Ber- 
muda (Aurelia, 1970). There was no evidence that 
the larvae survived and set in estuarine waters in 
the Cape Canaveral area. Relatively few spat 
were caught at Port Canaveral RWR6 Buoy, the 
site closest to shore and to an estuarine inlet 
(Figure 2, Table 1). Furthermore, a year-long 
biofouling study at nearby Ponce de Leon Inlet 
produced three species of mollusks, but no 
scallops (Richards and Clapp, 1944). 

Larval calico scallops are apparently 
distributed throughout the water column, since 
spat were found in traps positioned at the ocean 
surface, at intermediate depths, and near the bot- 
tom (Table 3). Similar vertical distribution of lar- 
vae was indicated by Pequegnat and Pequegnat 
(1968) who reported calico scallop spat from 
biofouling arrays distributed from surface to bcjt- 
tom in 46 m of water in the northeastern Gulf of 



below ocean surface, intermediate traps 6.0 m 
above ocean floor. 

Mexico. Off Cape Canaveral at Buoys 1 and 2, 
from April 20 to May 25, 1971, there were very 
few spat in the surface traps as compared with 
those in the intermediate and bottom traps. At 
each of these two sites, comparisons of in- 
termediate and bottom catch rates between 
November 1970 and October 1971, showed that 
vertical distribution of spat was highly variable 
during certain exposure periods, indicating varia- 
tions in larval abundance or spat survival be- 
tween the intermediate depths and the bottom at 
these seasons (Table 3). 

Calico scallop spat were caught year-round in 
traps off Cape Canaveral; at least a few spat 
were caught during every exposure period (Table 
2). This suggests continuous recruitment of young 
scallops to the population on the grounds, 
although there may not be a simple relationship 
between setting success in the traps and success 
on natural substrate in the immediate area. For 
example, while the numbers of spat at Buoy 1 
generally exceeded those at Buoy 2 (Table 2), 
trawl catches of adult scallops on the ocean floor 
at Buoy 2 greatly exceeded those at Buoy 1. The 
substrate at Buoy 1 consisted of sand and flat 
conglomerate rocks, while that at Buoy 2 was 
sand and live shell rubble. 



Ill thp: nautilus 



October 3U. 1979 



Vol.94 (4) 



There were distinct seasonal variations in spat 
abundance. At Buoy 1, between July 21, 1970 and 
October 27, 1971, catches ranged from 0.3 to 130.0 
spat per trap per day. Based on catches at Buo.v 
1, where the data are most complete, and sup- 
plemented by data from Port Canaveral R2 Buoy, 
the great majority of spat were caught in traps 
exposed between January 6 and June 26, 1971, 
with peak numbers from March 16 to April 20, 
1971. Relatively few spat were caught during the 
remainder of the year. A similar pattern of spat 
abundance occurred at Bu(jy 2(Table 2). 

Age and Growth 

Age and growth of young calico scallops were 
estimated from the maximum sizes of spat caught 
in the spat traps at the end of each exposure 
period. For example, spat traps exposed for 35 
days contained spat ranging from 0.25 to 10.0 mm 
shell height; the size composition from one trap 
is shown in Figure 5. Assuming no movement of 
spat into the traps after initial setting, the set- 
ting time of these scallops had to be within the 
35-day exposure period. Under laboratory condi- 
tions, calico scallop larvae set 16 days after 
spawning, at about 0.25 mm shell height (Costello 
et al., 1973). Therefore, age of the 10.0 mm spat in 
the traps could not exceed 51 days (16 days from 
spawning to set, plus a maximum of 35 days in 
the traps.) In estimating growth, it was assumed 
that the largest spat in the traps (10.0 mm .shell 
height) set on the first day of trap e.xposure. 
Evidence that spat set soon after the traps were 
exposed was based on the size ranges of spat in 





1 234567B9I0 
SHELL HEIGHT IN MILLIMETERS 

FIG, .5. Size composition of calico scallop spat from spat trap 
exposed at Biuiij 1 off Cape Canaveral Florida, April 20 to 
Mail £>. 1971. 



ACE rN DAYS 

FIG. (). KsliiHuted aye and yrimih of eidico scallop spat from 
spat traps exposed off Cape Canaveral. Florida March 1970 to 
Cktober 1971. Age U number of days from spawning to set 
I Hi) plus number of days of spitt trap exposure. 

traps exposed for short periods of time. In one 
trap exposed for 11 days, many spat from 0.25 to 
1.0 mm shell height were found. Since spat set at 
0.25 mm shell height, it is reasonable to expect 
that the 1.0 mm .spat set first, on or soon after 
the first day of trap exposure. While this 
assumption regarding time of spat setting may 
not be entirely correct for all situations, it is 
probably the best assumption that can be made 
based on the available data. If it is assumed that 
the largest spat set after the first day of trap ex- 
posure, then estimated growth would be more 
rapid than reported here. 

Tliis method of estimating age as related to 
size was applied to the largest spat from each ex- 
posure period and the results are shown in 
Figure 6. Based on these data, calico scallops are 
capable of reaching approximate sizes of 1.5 mm 
shell height in 1 month from spawTiing, 17.0 mm 
in 2 months, and 28.0 mm in 3 months. This 
growth rate is compatible with results of 
preliminary studies of marked calico scallops on 
the Cape Canaveral grounds, reported by Miller 
and Hudson', which indicate that scallops reach 
40 to 45 mm shell height in 6 to 8 months. 



' Miller, G. C. and J. H. Hudson. Age and growth of the calico 
scallop, Argopecten gibbits. Manuscript in preparation. Na- 
tional Marine Fisheries Service. Southeast Fisheries Center. 
Miami Laboratory. Miami. FL :fil49. 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 115 



Preliininaiy studies indicate that growth rate 
of spat in the traps is affected by location in the 
water column and, probably, by the density of 
spat. At Buoy 2, spat in a trap 0.6 m above the 
ocean bottom grew more rapidly than those in 
traps 6.0 m off the bottom and 0.9 m below the 
water surface. Similarly, Merrill and Posgay 
(1968) observed that juvenile sea scallops grew 
faster on the ocean bottom than on navigation 
buoys. Also at Buoy 2, in three traps located 0.6 
m off the bottom and exposed for 72 days, the 
maximum size of spat in each trap decreased 
with increased number of spat per trap. 

Behavior 

Information concerning setting and byssal at- 
tachment of calico scallops in respect to size has 
been reported briefly. The larvae set at about 0.25 
mm shell height in the laboratory (Gistello ct al., 
1973). Calico scallop spat have been reported by 
size and attachment as follows: 1 to 8 mm 
(presumably shell height) from plastic floats (Pe- 
quegnat, Gaille, and Pequegnat, 1967); 2.0 to 7.5 
mm shell length, among epifauna on shells of liv- 
ing calico scallops (Wells, Wells, and Gray, 1964); 
and 3 to 5 mm shell length, attached to the shells 
of dead calico scallops, primarily (Commercial 
Fisheries Review, 1962). 

The sea scallop showed a progressive loss of 
byssal attachment as size increased (Caddy, 1972). 
The calico scallop apparently behaves similarly, 
from observations on recovered spat traps. Off 
Cape Canaveral, setting apparently occurred at a 
minimum size of 0.25 mm shell height, since this 
was the minimum size of spat in the trap 
samples. Strong byssal attachment to the ex- 
teriors of the traps was shown by spat up to at 
least 5.0 or 6.0 mm shell height. Very few spat 
larger than 10.0 mm in height were found at- 
tached to the exteriors of the traps at recovery, 
although many spat larger than 10.0 mm were 
contained inside the traps where escape was im- 
possible. This size difference suggests weakened 
byssal attachment by the larger spat, since most 
had apparently detached from the e.xteriors of the 
traps upon reaching 10.0 mm shell height or were 
dislodged during trap recovery. Calico scallops as 
large as 38 mm shell height occasionally wei-e 
found attached to dead scallop shells in trawl 
catches on the Cape Canaveral grounds. From 



observations on calico scallops resting on the bot- 
tom, in Bermuda, Waller (1973) reported "The 
majority of the largest individuals [50 to 60 mm 
shell height] lie free, without byssal attachment, 
although many mature individuals attach a weak 
byssus to dead shell and coral fragments." 

A>i!^uciated Orgarmms 

Setting, growth, and survival of scallops are 
positively influenced by certain sessile plants and 
animal which form a hospitable habitat. Young 
bay scallops attached to seagrass (Belding, 1910), 
algae (Marshall, 1960), and hydroids (Zahl, 1969). 
Young kelp scallops, Leptopecten latiauratus 
were found in the interstices of erect bryozoans 
(Brown et al., 1967) and attached to colonial in- 
vertebrates (particularly hydroids) and algae 
(Turner, Ebert, and Given, 1969). According to 
Dow (1969), young sea scallops first set on bryo- 
zoans that are attached to adult scallop shells 
and at a larger size, attached themselves directly 
to shells or bottom debris. Merrill and Edwards 
(1975) noted, however, that sea scallop spat will 
set "on sedentary branching plants and animals, 
or- any other hard surface on or above the ocean 
floor which offers freedom of shell movement on 
all sides." 

Before the inception of the calico scallop spat 
monitoring study, most calico scallop spat had 
been caught by trawl or dredge. Under these cir- 
cumstances, spat as small as 3.0 mm shell length 
were found attached to the dead shells of calico 
scallops (Commercial Fisheries Review, 1962). 
Primary setting of very small calico scallop spat 
on filamentous plants or animals before attach- 
ment to mollusk shells was not reported. 
However, spat 2.0 to 7.5 mm shell length were 
among the epifauna attached to the shells of liv- 
ing calico scallops (Wells, Wells, and Gray, 1964). 
In addition, calico scallops 1 to 8 mm 
(presumably in shell height) were reported from 
plastic floats (Pequegnat, Gaille, and Pequegnat, 
1967). Attachment, in the last two cases, was not 
necessarily directly to the shells or floats, but 
perhaps to the "pioneer" fouling organisms 
already affixed. Data presented by Pequegnat, 
Gaille, and Pequegnat (1967) indicated that calico 
scallop spat occurred in greater numbers on 
plastic floats exposed 8 and 12 weeks than on 
floats exposed 2 and 4 weeks, and that the floats 



116 THE NAUTILUS 



October 30, 1979 



Vol. 94 (1) 



Table 4. 



Estimated spawning periods of calico scallops oft Cape Canaveral, 
July 1970 to September 1971. 



Florida, 



Spat trap exposure 
periodl- 


Catch of 
spat 


Mlmlmura 
spat size 


Estimated 
age of spat 


Estimated spawning 
period 






(per day) 


(mm) 


(days) 








7/21/70 - 


8/26/70 


6.5 


3.U 


39 


7/05/70 




- 7/18/70 


8/26/70 - 


11/11/70 


0.5 


4.0 


44 


8/10/70 


- 


9/28/70 


U/U/70 - 


1/24/71 


1.8 


1.0 


27 


10/26/70 


- 


12/28/70 


1/06/71 - 


2/16/71 


9.4 


0.75 


23 


12/21/70 


- 


1/24/71 


1/24/71 - 


2/16/71 


15.7 


O.S 


20 


1/05/71 


- 


1/27/71 


1/24/71 - 


3/16/71 


13.6 


1.5 


32 


1/08/71 


- 


2/12/71 


3/16/71 - 


4/20/71 


130.3 


1.0 


27 


2/28/71 


- 


3/24/71 


4/20/71 - 


5/25/71 


65.7 


1.0 


27 


4/04/71 


- 


4/28/71 


5/2 5/71 - 


6/26/71 


72.5 


1.0 


27 


5/09/71 


- 


5/30/71 


6/26/71 - 


8/24/71 


2.4 


0.75 


23 


6/10/71 


- 


8/01/71 


8/24/71 - 


10/27/71 


0.3 


4.0 


44 


8/08/71 


- 


9/13/71 



1 Traps «ere located at Buoy 1 except fo 
1/24/71 to 2/16/71, which were at Port 
about 0.6 m above the ocean floor. 

acquired growths of hydroids before calico 
scallops became present. 

During the present study, filamentous marine 
plants and animals were found attached to array 
lines and spat traps. On more than one occasion, 
small calico scallop spat 0.75 to 4.5 mm shell 
height (mostly 1.5 to 2.0 mm) were found among 
attached hydroids (unidentified). Attempts at sea 
to determine if spat were byssally attached to the 
hydroids, rather than directly to array lines or 
spat traps, were unsuccessful because of rough 
sea ronditions, and live spat had detached before 
microscopic examination could be made. These 
observations suggest, however, that very small 
calico scallop spat may utilize filamentous host 
organisms for setting, perhaps before later at- 
tachment directly to shell. A cycle of dependence 
may be operating, since certain species of 
hydroids and erect bryozoans, which may host 
calico scallop spat, were reported by Wells, Wells, 
and Gray (1964) as common among epifauna at- 
tached to the shells of living calico scallops. 

Most organisms in the spat traps apparently 



r those exposed from 1/06/71 to 2/16/71 and 
Canaveral R2 Buoy. All traps were positioned 

arrived as planktonic larvae and included 
numerous invertebrates (coelenterates, annelids, 
mollusks, echinoderms, crustaceans, and 
tunicates) and, rarely, fishes. Calico scallops were 
generally the dominant macroscopic animals in 
respect to biomass and, with the possible excep- 
tion of amphipods, in numbers. Barnacles were 
common in the traps and were sometimes 
attached to calico scallop spat. At least some bar- 
nacles attach when calico scallops are young: a 
barnacle 2.0 mm diameter at its base was found 
attached to a spat 5.0 mm shell height. 

Ecological .succession in the spat traps may 
have been modified or hastened by the effect of 
the filamentous strands of polyethylene. Contents 
of one spat trap exposed for only 11 days in- 
dicated veiT rapid development of the biofouling 
community or assemblage. Included were 121 
calico scallop spat 0.25 to 1.0 mm shell height, 125 
gastropod mollusks, and 250 amphii>)ds. Tliere 
were less than 10 each of bivalve mollusks (other 
than calico scallops), isopods, copepods. mysids, 
crabs, and polychaetes. 



Vol.M (4) 



October 30, 1979 



THE NAUTILUS 117 



ADULTS 

Spawning 

The abundance and size of calico scallop spat 
caught during successive trap exposure periods 
were used to estimate the season and intensity of 
adult spawning. The size of the smallest spat 
caught during each exposure period (Table 4) was 
related to age (Figure 6). For spat caught during 
each exposure period, spawning was estimated to 
have extended from 16 days before the trap was 
first exposed to the date the trap was recovered, 
less the age in days of the smallest spat caught. 
It was assumed that spat abundance primarily 
reflected seasonal spawning intensity, rather 
than variations in survival of larvae and spat. 
Estimated spawning periods from July 1970 to 
October 1971 are shown in Table 4. Spawning ap- 
parently occurred during all seasons, but intensi- 
ty was greatest in the spring. Following low 
spawning intensity in July, and lower intensity 
from August into December, spawning increased 
in late December or January and peaked in 
March. High spawning intensity continued 
through April and May, followed by an abrupt 
decrease in June and low spawning intensity into 
September. 

There is no direct evidence that spat setting on 
the Cape Canaveral grounds are entirely or par- 
tially the first generation progeny of scallops 
spawning in that area. However, the spawning 
pattern determined from seasonal distribution 
and abundance of spat in this study is similar to 
the spawning pattern determined from ovarian 
color changes of calico scallops on the Cape 
Canaveral grounds (Roe, Cummins, and Bullis, 
1971; Miller, Allen, Costello, and Hudson'). Fur- 
thermore, as explained previously, water circula- 
tion in the Cape Canaveral area might be ex- 
pected to retain scallop larvae on the grounds un- 
til setting occurs. 

Spawning of calico scallops, similar to spawn- 
ing of other bivalves, is influenced by water 



' Miller. G. C. D. M. Allen. T. J. Costello. and .J. H. Hudson. 
Maturation of the calico scallop. Argapecten gibbus. deter- 
mined by ovarian color changes. Manuscript in preparation. 
National Marine Fisheries Service, Southeast Fisheries 
Center, Miami Laboratory, Miami, FL 33149. 



temperature changes. In the laboratory, spawning 
of ripe calico scallops was induced by raising 
water temperatures from about 20° to 2.5°C 
(Cxi.stello et ai, 1973), but these temperatures are 
not necessarily critical for spawning. In the 
natural environment off Cape Canaveral, daily 
mean temperatures of bottom water at Buoys 1 
and 2 are available for most of the period from 
March 28, 1970 to August 24, 1971, and ranged 
(combined) from 16.3° to 26.9°C (Leming, 1979). 
During the period of apparent minimum spawn- 
ing, August through November 1970, bottom 
temperatures at these sites ranged from 18.3° 
to 26.9°C, while during apparent maximum 
spawning, March through May 1971, tempera- 
tures fluctuated between 16.9° and 22.0°C. 
Temi^eratures at Buoys 1 and 2, however, were 
recorded in water 18 and 22 m deep, shoaler than 
the 28 to 65 m depths where most of the scallops 
occur off Cape Canaveral (Allen and Costello, 
1972). Therefore, the temperatures at Buoys 1 and 
2 often varied from those associated wdth the 
large concentrations of scallops in deeper water. 
On the shelf off Cape Canaveral there was a 
general onshore movement of 18°C bottom water 
beginning in March 1971 (Leming, 1979). This 
cold water passed over the concentrations of 
scallops expected to be mostly ripe during March, 
April, and May and perhaps triggered successive 
spawning. 



DISCUSSION 

The spat monitoring techniques used in this 
study were useful in determining certain 
preliminary information concerning the biology 
of the calico scallop. However, ecological succes- 
sion and other alterations with time in an ex- 
posed spat trap provide a continually changing 
environment, affecting both spat setting and sur- 
vival. In this low-priority study, the scheduling of 
trap exposure was governed by the availability of 
ship time. In future studies to measure seasonal 
abundance and distribution of spat, monitoring 
should be further standardized by scheduling trap 
exposure for relatively short time periods of 
uniform length and interval throughout the year. 
These refinements would also serve to more 
precisely fix spawning time and provide measures 



118 THE NAUTILUS 



October 30. 1979 



Vol.94 (4) 



of early spat growth by season. Expansion of spat 
monitoring over wider areas, both on the Cape 
Canaveral grounds and on the Florida-Hatteras 
and West Florida shelves, would provide insight 
into the origin of the larvae and the relationship 
of varying water temperature regimes to spawn- 
ing, setting, and survival. 

ACKNOWLEDGMENTS 

I thank George C. Miller. National Marine 
Fisheries Service. Southeast Fisheries Center, 
Miami Laboratory, Miami. Florida, for useful 
discussions concerning the manuscript, and for 
the photograph for Figure 4. 



LITERATURE CITED 

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Argopecten giblnui. NOAA Tech. Rep. NMFS SSRF-&56, 19 p. 

Aurelia. M. 1970. The habitats of some subtidal pelecypods in 
Harrington Sound, Bermuda. //( Robert N. Ginsburg and 
Steven M. Stanley (editors). Reports of research. 1969, 
Seminar on organism-sediment interrelationships, p. •39-.52. 
Bermuda Biol. Sta. Res. Spec. Publ. No. 6. St George's 
West, Bermuda. Sponsored by the National Science Founda- 
tion Grant No. GB 1.3678. 

Belding, D. L. 1910. A report upon the scallop fishery of 
Massachusetts, including the habits, life history of Pecten 
irradians. its rate of growth, and other facts of economic 
value. Wright & Potter Printing Co., Boston, 150 p.. 118 
figs. 

Brown, N. L.. .J. E. Jaeger, F. T. Kleber. and N. F. North. 
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U.S. Navy Office of Naval Research Contract Nonr 4.5.32 (00) 
Project No. NR 083-19.5. 79 p. 

Bumpus. D. F. 197.3. A de.scription of the circulation on the 
Continental Shelf of the east coast of the United States. In 
B. A. Warren (editor). Progress in Oceanography 6:111-1.57. 
Pergamon Press, New York. 

Caddy. .J. F. 1972. Progressive loss of byssus attachment with 
size in the sea scallop, Plampecten magellaniais (Gmelin). 
J. Exp. Mar. Bio. Ecot. 9: 179-190. 

Calder. D. R. and M. L. Brehmer. 1967. Seasonal occurrence of 
epifauna on te.st panels in Hampton Roads, Virginia. Int. J. 
()cean<,l. Limnot. I:li9-IM. 

Commercial Fisheries Review. 1962. Calico scallop explora- 
tions off North Carolina: M/V Silver Bay Cruise 39. Com- 
mer. Fith. Rev. 24(8):38-39. 

Cory. R. L. 1967. Epifauna of the Patuxent River &tuary. 
Maryland, for 1963 and 1964. Chesapeake Sci. 8:71-89. 

Costello, T. .J., J. H. Hudson, ,1. L. Dupuy, and S. Rivkin. 197a 
Larval culture of the calico scallop. Argopecten gibbtis. 
Proc. Nat. Shellfish. Assoc. 63:72-76. 



Costlow. J. D.. .Jr. (editor). 1969. Proceedings of the Fifth In- 
terdisciplinary Conference on Marine Biology. Marine 
Biology. 5. Gordon and Breach, Science Publishers. New 
York. 606 p. 

Cummins. R.. Jr. 1971. Calico scallops of the southeastern 
United Stotes, 1959^. Natl. Mar. Fish., Spec. Sci. Rep. 
Fish. 627. 22 p. 

DePalma. J. R. 1969. A study of deep ocean fouling Straits of 
Florida and Tongue of the Ocean 1961 to 1968. U.S. Naval 
Oceanogr. Office. Washington, DC. Informal Rep. No, 69-22, 
26 p. 

Dix, T. 1977. Life histories of bivalve mollusc larvae. 
Australmn Fish. 36 (8):8-9, 1.5. 

Dow. R. L. 1969. Sea scallop fishery. In F.E. Firth (editor). 
The encyclopedia of marine resources, p. 616-623. Van 
No.strand Reinhold Co., New York. 

Drummond, S. B. 1969. Explorations for calico scallop, Pecten 
gihbux. in the area off Cape Kennedy, Florida, 1960-66. Fish. 
ImL Res. 5:8.5-101. 

Golikov. A. N. and 0. A. Scarlato. 1970. Abundance, dvTiamics 
and production properties of edible bivalves Miziihopecten 
yessoensis and Spisida sachalinensis related to the problem 
of organization of controllable submarine farms at the 
western shores of the Sea of Japan. Helgol. Wiss. 
Meeresunters. 20:498-513. 

Kirby-Smith. W. W. 1970. Growth of the scallops, Argopecten 
irradians concentriciis (Say) and Argopecten gibhiis (Linne), 
as influenced by food and temperature. Ph.D. Dissertation. 
Duke Univ.. Durham, N.C., 127 p. 

Leming. T. D. 1979. Observations of temperature, current, and 
wind variations off the central eastern coast of Florida 
during 1970 and 1971. NOAA Tech. Mem. NMFS-SEFC-6. 
172 p. 

Loosanoff, V. L. 1966. Time and intensity of setting of the 
oyster. Crassostrea mrginica, in Long Island Sound. BioL 
Bull (Woods Hole) 130:211-227. 

Marshall. N. 1960. Studies of the Niantic River, Connecticut 
with special reference to the bay scallop, Aequipecten irra- 
dians. Limnoi Oceanogr. 5:86-105. 

Merrill. A. S. 1965. The benefits of systematic biological col- 
lecting from navigation buoj-s. ASB (Assoc. Southeast. Biol.) 
Butt. 12:3-8. 

Merrill. A. S. and R. L. Edwards. 197.5 Observations on 
mollusks from a navigation buoy with special emphasis on 
the sea scallop, Placopecten mageUanictis. The NaiUilns 
89:116-123. 

Merrill, A. S. and J. A. Posgay. 1968. Juvenile growth of the 
sea scallop, Placopecten magellanicus (abstract). Amer. 
Malacol Union. Ann. Rep. 1967, p. 51-52. 

Petiuegnat. W. E., R. S. Gaille. and L.H. Pequegnat. 1967. 
Biofouling studies off Panama City, Florida. II. Vne two 
mile offshore station. Texas A&M Univ., Dep. Oceanogr. 
Proj.286-6.Ref67-18T.47p. 

Pequegnat, W. E., and L. H. Pequegnat. 19(>8. Ecological 
aspects of marine fouling in the northeastern Gulf of Mex- 
ico. Texas A&M Univ., Dep. Oceanogr. Proj. 286-6. Ref 68- 
22T,80p. 

Richards, B. R. and W. F. Clapp. 1944. A preliminary report 
on the fouling characteristics of Ponce de Leon Tidal Inlet, 
Dajtona Beach. Florida.. A/Hr. Mar Res. ,5:189-195. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 119 



Roe, R. B., R. Cummins, Jr, and H. R. Bullis, Jr. 1971. Calico 
scallop distribution, abundance, and yield off eastern 
Florida, 1967-1968. Fi.s/t. Bull, U.S. 69:399-409. 

Shaw, W. N. 1967. Seasonal fouling and oyster setting on 
asbestos plates in Broad Creek, Talbot County, Maryland. 
1963-6.5. OiempeakeSch 8:228-2:36 

Turner, C. H., E E Ebert, and R. R. Given. 19(i9. Man-made 
reef ecologj'. Cnlif. Dtp. Fi.ih Cktnit'. Fish. Bull. 146, 221 p. 

Waller, T. R. 1969. The evolution of the Argopcrtcii gihhiix 
stock (Mollusca:Bivalvia), with emphasis on the Tertiary 
and Quaternary species of eastern North America. Paleait- 
tol. Soc. Mem. 3, 125 p. Also J. Paleontol. 43 (Suppl. to No. 
5). 



1973. The habits and habitats of some Bermudian 

marine mollusks. Ihc Nuiitilu.'i 87:31-.52. 
Wells, H. W., M. .1. Wells, and I. E. Gray. lillU. The calico 

scallop community in North Carolina. Bnll. Mar. Sci. (itdf 

Caribh. 14:561-.593. 
Woods Hole Oceanographic Institution. 1952. Marine fouling 

and its prevention. U.S. Naval In.st., Annapolis, Md. 

(Prepared for Bur. Ships, Navy Dep., by Woods Hole 

Oceanogr. lnst.,Contrib. No. .580). 388 p. 
Zahl, P. A. 1969. The magic lure of sea shells. Natl. Geoyr. 

Mag. 135:386-429. 



FACTORS INFLUENCING DISTRIBUTION OF MUSSELS IN THE 
BLANCO RIVER OF CENTRAL TEXAS 

Francis R. Home and Steve Mcintosh 

Department of Biology 

Southwest Texas State University 

San Marcos, Texas 78666, U.S.A. 

ABSTRACT 

Enr)7-<»}me)ital parameters that influence the di^tnhution of eight mussels in 
the Blanco River of Central Texas were studied. Tlie effects of type of substrate, 
stream flow rate and physicochemical features on mussel distribution were 
evaluated, hut emphasis ivas given to the role of organic enrichment of the river 
by a city sewage treatment plant. From tolerance tests to ammonia and low ox- 
ygen on five local mussels and from field .studies, the follounng remarks can he 
made about mussel distribution in the Blanco River. 

(1) Low dissolved o.tygen levels (0 - (1.5 mg (\ l~^j proved lethal to Jt7"/u of the 
mwssels tested in seven days. 

(2) Levels of .5 mg NH+4 - NH.t' (pH 7.S to H.O: NH, - N = 0.211 mg -1) were 
lethal to W% of the mus.sels tested in seven days. 

(3) Corbicula manilensis was more tolerant, and Amblema p. plicata less 
tolemnt than the other mussels tested to elevated ammonia and low oxygen cim- 
centrations associated mth .sewaj/e emichment. 

iU) Even though the physicochemical parametets did not indicate stressful condi- 
tions on the d,ays sampled, mussels of the Blanco River seemed to have been 
adveisely effected by emichment from the secondary sewage treatment plant <f 
San Marcos. Fewer mussels were found downstream from the sewage phuit than 
upstream, even where the river baftmn. depth, and flow rates ivere similar. 



INTRODUCTION 

The use of freshwater mussels (Bivalvia) as 
aquatic indicators of ecological changes brought 
about by agriculture, mining practices, effluents 
from industrial and/or domestic disposal plants 
has not been studied extensively. Freshwiiter 
mussels might be valuable indicatm-s of Ixith |)ast 



and present ecological conditions of aquatic en- 
vironments. 

For the following reasons, mussels might be 
especially good as indicators of stream conditions. 

(1) Unlike plankton or free swimming fauna, 
bivalves as benthic invertebrates usually remain 
in relatively fixed positions in streams (Weber 
1973). 



120 THE NAUTILUS 



October W, 1979 



Vol.9} (1) 



(2) Mussels ain directly alisorb nutrients, sim- 
ple orpanic connpounds (Churchill 1916) and 
various pollutants. Such pollutants might be 
pesticides, radioactive materials and heavy 
metals which often would show up in biologically 
magnified concentrations (Weber 1973; Butler 
1965: Fuller 1974: Bedford et d. 1968; Mathis 
and Cummings 1973). Bivalves also indirectly 
reflect ecological conditions by taking up 
pollutants by feeding from the bjusic trophic 
levels or aquatic food chains (Fuller 197 1). 

(3) The freshwater mussels (Unionacea) have 
relatively long life cycles, up to 17 years and 
longer (Williams 1969; Bedford et d. 1968). 
Therefore, their community and population struc- 
tures are accumulatively affected by environmen- 
tal perturbations (Weber 1973). 

(4) Unlike periodic chemical analyses, the ben- 
thic mussels are continuously exposed, except 
when buried, to the water conditions and might 
reflect variable or infrequent discharges of 
pollutants (Weber 1973). 

Our present knowledge is insufficiently 
detailed, however, to define Unionaceae or 
Sphaeriidae (Pisidiidae) as pollutional indicators 
in chemical terms (Fuller 1974; Ingram 1967). A 
great deal of work needs to be done on identify- 
ing the reactions of bivalves to specific natural 
factor's in the environment, and on the reactions 
of mollusks to pollutants (Butler 1965). 

Recently, Neel and Allen (1964) noted the 
decimation of various mussel populations in the 
upper Cumberland Basin by coal mine acids, 
while Charles (1964) found that very heavy 
populations of mussels have been virtually 
destroyed by brine pollution from oil wells. Even 
potassium has been suggested to regulate the sur- 
vival and distribution of freshwater mussels 
(Imlay 1973). 

Because they concentrate certain pollutants 
otherwise not detectable in water or sediments, 
mussels have been utilized as indicators of 
pesticide and metal pollution (Bedford et d. 1968; 
Mathis and Cummings 1973). The bivalves concen- 
trated both pesticides and metals in higher con- 
centrations than was found in the surrounding 
water, but contained lower levels of most of these 
toxic compounds than occurred in sediments. 
Possibly the best utilization of freshwater 
mussels as indicators of stream conditions is as 



"indicators of the biological rec-overy zone" 
(Simons and Reed 1973). 

The purpose of the current study was to explore 
the environmental parameters that influence 
distribution of mussels in the Blanco River. Special 
emphasis was given to the effects of organic enrich- 
ment of the river by a city sewage treatment 
plant. Tolerance tests to ammonia and low ox- 
ygen on five species of local mussels were con- 
ducted in the laboratory in an atempt to evaluate 
such enrichment. 

STUDY AREA 

The Blanco River is located at the headwaters 
of the Guadalupe River Basin in central Texas. 
The Blanco River flows over the Edwards Plateau 
and joins the San Marcos River approximately 4 
km east of the perimeter of the plateau. The Ed- 
wards Plateau is composed of uplifted limestones 
that contribute to the natural calcareous hard- 
ness of the Blanco River. At the Kyle sampling 
station the mean annual flow for a 19 year 
sampling period was 4.3 m^ sec"' (U.S.G.S. 1976). 
At the Kyle gauging station, about 9 km 
upstream from the study area, no flow levels oc- 
curred in the summers of 1956, 1963, 19(>4 and 
twice in 1971 (U.S.G.S. 1976). Except during 
periods of flooding, the lower portion of the 
Blanco River is usually transparent enough for a 
visual analysis of the substrate. 

The drainage basin of the Blanco River above 
the Kyle sampling station is 1,(X)7 sq. km. and 
contains little arable land. Most of the basin is 
sparsely populated, and agriculture consists 
mainly of grazing with only limited crop farming 
on the rocky terrain. After the Blanco River 
leaves the plateau, the river traverses a more 
populated area where crop farming predominates. 

Sampling areas on the Blanco River were 
located between 29°55'— 29°5r latitude and 
97°55'— 97°54' longitude. The study area consisted 
of a 6 km stretch of the Blanco River located just 
upstream of the confluence of the San Marcos 
River (Fig. 1). A secondary sewage treatment ef- 
fluent enters the Blanco River approximately 2 
km downstream from the headwaters of the study 
ai^a. The sewage effluent, except under very low 
flow conditions, is diluted naturally by a side 
channel of the river before it reaches the main 
stream. In the faster moving waters of the 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 121 




FIG. 1. Location of sampling sites on the Blanco River. Texas. 

diluted side channel, toxicity study areas were 
established about 50 m before and after the point 
of entry of the sewage. Three sampling stations 
for physicochemical analyses of the river were 
located (1) about 50 m above (Station 3), (2) 200 
meters (Station 4) and (3) 2 kilometers below 
(Station 6) the site where the sewage effluent 
enters the river (Fig. 1 ). 

METHODS AND MATERIALS 
Qualitative and Quantitative Determinations 

Qualitative and quantitative mussel counts 
were performed at mid-day by visual inspection 
while wading or scuba diving in the deeper pools. 
The entire study area was quantitatively sampled 
for freshwater mussels. Three quantitative counts 
were made at stations above, and two quan- 
titative counts below the sewage effluent (Fig. 1). 
Quantitative counts were made in 10 m^ areas 
utilizing ten one meter transects. After identify- 



ing and recording the specimens, they were lifted 
from the substrate to prevent duplications. Only 
those individuals exposed or actively siphoning in 
the substrate were utilized in the quantitative 
determinations. 

Mussel specimen identifications were made 
utilizing the taxonomic keys of Burch (1973), 
Murray (1%2; 1968), Simpson (1913) and Strecker 
(1931). Identifications were checked and verified 
by Dr. H. D. Murray of Trinity University in San 
Antonio, Texas, and Dr. David Stansbery of Ohio 
State University in Columbus, Ohio. Specimen 
were deposited at Ohio State University (Collec- 
tion Numbers OSUM: 1976: 352-361). 

Tolerance Tests 

Specimens utilized in the tolerance tests were 
collected in central Texas near the study area. 
The specimens were then placed in aerated 
aquaria for a minimum of five days for acclima- 
tion to laboratory conditions. During the period 
of acclimation and testing, the experimental and 
control specimens were not fed. Before being 
utilized in the toxicity tests each laboratory 
specimen was washed and scrubbed to remove 
adhering organisms. The ventral margins of the 
bivalves were notched with a triangular file so 
that the bivalves would be constantly exposed to 
the stressors. At least eight specimens of each 
species were utilized in the toxicity tests. 

The chlorine content of the tap water used in 
the experiments ranged from 0.2 - 0.4 mg 1"' and 
was removed from the test waters by aeration or 
bubbling nitrogen. The total alkalinity of the 
water varied from 200 to 250 mg 1"' and 
depended upon the stressor(s) utilized The total 
alkalinity of water from which the organisms 
were collected varied from 150 to 200 mg 1"'. The 
temperature of the experiments was ambient 
room temperature which was usually between 
24°— 26° C. The hydrogen ion concentration (pH) 
ranged between 7.8 and 8.2 during the laboratory 
experiments. At an average pH of 8.0 a solution 
containing ammonia (NH-I-4 -NH3) would consist 
of 94.7% ammonium ions and 5.3% ammonia gas 
(NH3). In this manuscript the term ammonia 
refers to both the ionic and gaseous form, even 
though the gaseous ammonia is the toxic form. 

At no time were moi'e than four larger mussels 
used in a single experiment. The bivalves 



122 THE NAUTILUS 



October 30. 1979 



Vol. 94 (4) 



Table 1. Substrate related distribution of freshwater mussels in the Blanco River. 



Species 



Stream Bottom 



Boulder 



Cobble 



Gravel 



Pebbles 



Sand Silt-mud 



Amblema £. 
plicata 

Anodonta 

imbecillis 

Corbicula 

manilensis 

Cyrtonaias 

tampicoensis 

Lampsilis a. 

anodontoides 

Lampsilis 
bracteata 

Quadrula 
petrina 

Toxolasma 

texasensis 



+++ = More than S/m^ 

++ = 1-5/m^ 

+ = Less than l/m^ 

- = Not Found 

Amblema p. plicata (Say, 1817), Anodonta im- 
hecillis (Say, 1829), Corbdcula manilensis (Philip- 
pi, 1844), Ci/Honaias tampicnen.'iis (Lea, 1838), 
Toxolasma texasensis (Lea, 1857) (^Cairunculina 
parva texasensis) were subjected to laboratory 
tolerance tests for 168 hours. Specimen were 
removed from the testing apparatus after failure 
to respond to physical stimuli by closure of the 
valves. Death was established when the mussels 
did not respond by attempted closure when their 
valves were partially pried apart. 

Low oxygen tolerance tests (0 - 0..5 mg 2 1 '') 
were performed in a modified 8 liter desiccator 
with a regulated water flow of about 300 ml 
hr.''. A 16 liter reservoir of water was deo.x- 
ygenated by bubbling prepurified nitrogen gas. 
The deoxygenated water was mixed with a 
magnetic stirrer and forced through the testing 
apparatus with low N2 pressure. Water samples 
for chemical analyses were taken from the testing 
apparatus by removal and subsequent replace- 
ment of standard biochemical oxygen demand 
(BOD) bottles that were situated before and after 
the specimen container. By maintaining the flow 
at least 300 ml hr"' the dissolved oxygen (DO) 
levels of the incoming and outflowing waters of 
the specimen container were similar. 



In the combination high ammonia and low ox- 
ygen tolerance tests the water was deoxygenated 
first and ammonia then added to the above 
testing apparatus. In both the combination high 
ammonia-low oxygen and high ammonia 
tolerance tests, ammonia levels of 5 ± 0.5 mg 1"' 
(NH^ -N = 0.26 mg l"') were obtained by the ad- 
dition of ammonium bicabonate. Bunkhalter and 
Kaya (1977) estimated 0.25 mg NH^-Nl"' to be 
the incipient lethal threshold concentration for 
rainbow trout fry. 

High ammonia tolerance tests were performed 
in 8 liters of aerated tap water in covered 
aquaria. Samples for chemical analyses were 
made by removal and subsequent replacement of 
similar amounts of water from the aquaria. 

Tlie tolerance tests in the Blanco River were 
performed in a side channel which contained 
diluted .sewage. The bivalves Amblema p. plicata, 
Anadonta imbecillis. Curbicula manilensis and 
Cjfiionaias tampicoensis were put under stress. 
The mussels were placed in cages of 1/4 inch 
square mesh screen which were partially buried 
in the gravel substrate. The controls were located 
50 m above the point of entry of the sewage and 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 123 



were placed in a similar substrate. The side chan- 
nel toxicity tests were performed for one month 
periods. 

Statistical analyses of the toxicity studies were 
performed by single factor analysis of variance 
and after hypothesis rejection analyses were 
followed by the Student Newman Kuels tests for 
differences in population ranges (Zar 1974). The 
survival times in hours were used as the observa- 
tions in the statistical tests. Since the maximum 
utilizable value for sui-vival time was sometimes 
limited by the length of the toxicity test, inter- 
pretations of the above statistical analyses were 
conservative. 
Phymcochemical A nalyses 

Water samples were taken with 1 liter 
polyethylene bottles 0.3 m below the surface on 
sunny mid-day periods. Water temperature was 
taken at the same time 0.3 m below the surface 
in shaded areas. Qilorine levels were determined 
in the field. Stream velocities were measured 
with a U.S.G.S. Pigmy current meter. Gilorine 
levels were determined in the field, whereas 
samples for pH, alkalinity, DO, NH+4 -N, BOD5 
and total mercury were analyzed wdthin forty- 
five minutes of collection in the laboratory. 
Samples for the determinations of Kjeldhal 
nitrogen, total dissolved phosphate-phosphorus, 
and potassium were stored at -20°C and analyses 
were conducted within three hours of collection. 
Chemical analyses of water were performed ac- 
cording to Standard Methods for the Examina- 
tion of Water and Wastewater (A.P.H.A. 1975). 

Sediment analyses were performed utilizing 
the modified Wentworth grade classification 
(Home and Mclntyre, 1971 and Weber, 1973). The 
substrate was scooped into a container placed 
just downstream and analyzed using U.S. Stan- 
dard sieves. Hydrogen ion concentrations were 
determined with a standardized Beckman Expan- 
domatic pH meter. Total alkalinity analyses were 
performed by titration with 0.02N H2SO4 to a pH 
of 4..5. Dissolved oxygen determinations were per- 
formed utilizing the alkali-azide modification of 
the Winkler method. Ammonia nitrogen analyses 
were made by distillation of the ammonia into 
boric acid followed by nesslerization. Kjeldahl 
nitrogen determinations were made by sample 
digestion followed by distillation and nessleriza- 
tion. Total dissolved phosphate-phosphorus 



samples were first filtered through 0.45 micron 
filters and then treated to persulfate digestion 
and the color developed by the ascorbic acid 
method. Chlorine levels were determined utilizing 
the orthotolidine colorimetric methods. Total 
mercury analyses were performed by the cold 
vapor technique using a mercuiy analyses system 
connected to an atomic absorption spectro- 
photometer. Total potassium ion determinations 
were made utilizing an atomic absorption spec- 
trophotometer. 

RESULTS 

Qualitative Sampliny and Species Distribution 

Living specimens of eight species of freshwater 
mussels, and shells of Amdonta g. grandis (Say, 
1829) and Lampsilis anodontoides fallaciosa 
(Smith, 1899), were collected in the Blanco River 
study area (Table 1). 

The type of stream bottom and the corre- 
sponding flow patterns seemed to limit the 
distribution and perhaps the abundance of some 
of the species (Table 1). Local geologic formations 
(recent alluvium) and periodically high stream 
velocities created a bottom composed of a 
gravel-cobble substratum in the faster flowing 
portions of the stream. Only on the periphery of 
the larger pools where the current was slow was 
a mud-silt bottom found (Fig. 1). All species col- 
lected in the river were present, although 
sometimes sparsely, in mud-silt substrates. 

Individuals having relatively heav>' shells, such 
as Quadrula petrina and Amblema p. plicata, 
were the only species found in water's with 
average stream velocities of 1 m sec"' or greater. 
In these waters the bottom was typically com- 
posed of cobbles with some boulders and gravel 
present. Although Corbicula manilensis has a 
relatively thick shell its small size probably 
limits it from occurring in the swiftest waters 
(Table 1). 

Freshwater mussels with shells of intermediate 
thickness such as Ciirtonnias tampicoensis. Lamp- 
silk a. anodontoides (Lea, 1834) and Lampsilis 
bracteata (Gould, 1855) generally were found in 
regions of intermediate stream velocities (0.5 - 1 
m sec"') where the usual bottom comp<jsition was 
coarse and/or medium sized gravel. The very thin 
shelled Anodonta imbecillis and the small sized 
Toxolusma texasensis were restricted to areas 



124 THE NAUTILUS 



Octobei- :10, 1979 



Vf.l. 94 (4) 



with the finast types of substrate material (Table 
1). and both were rarely found in the river. 

Ph yiiicochemical Parameters 

During the sampling period from July, 1976, to 
June, 1977, the minimum flow was 1.5 m^ sec"' 
and the ma.\imum flow was about 112 m^ sec"' at 
the Kyle gauging station. Unlike previous years 
very low or no flow periods did not occur during 
the sampling year. Water temj^eratures varied 
from 11.5°C in January, 1977, to 31.0°C in August, 
1976. Secchi disc transparency varied from 0.8 m 
to 2.1 m in the Blanco River, (^nerally, trans- 
parency increased during low flow periods and 
decreased during high flow periods. 

The secondary sewage plant adjacent to the 
Blanco River usually received less than 30% of 
the total sewage load of San Marcos. The mean 
flow through the sewage treatment plant for the 
twelve month sampling period was 0.84 million 
gallons/day (mgd) with extremes of about 0.05 to 
1.1 mgd. 

For June, 1977, average effluent values for the 
treatment plants and the diluted sewage of the 
side channel are given in Table 2. Also for June 
the sewage enriched side channel of the Blanco 
River (Fig. 1) had a total flow of approximately 



0.1 m^ sec"' of which about 20 - 50% was sewage 
effluent, depending upon the amount of effluent 
discharged. During the same period, the Blanco 
River received an average of 110 kg BOD, day"', 
90 kg potassium day"', 50 kg of ammonia-N day"' 
and 9 kg of total phosphate-phosphorus day"' . 
The secondary treatment plant received waste 
from only the northeast portion of San Marcos. 

Total mercury analyses for the sewage effluent 
and water samples from the Blanco River in 
March, 1977, were below detectable limits (less 
than one microgram 1"'). Chlorine also was not 
detectable (less than 0.1 mg 1"') in the enriched 
side channel. Chemical parameters which were 
monitored at Stations 3, 4 and 6 (Fig. 1) are 
presented in Table 2. Where the sewage effluent 
entered the river, all parameters increased, ex- 
cept dissolved ox>'gen and pH. The largest in- 
creases occurred with ammonia and total 
dissolved phosphate which increased 300% and 
100%, respectively. At the sampling station 
located 2 km downstream from the treatment 
plant (Site 6), all parameters were more similar 
to the uncontaminated waters above the sewage 
effluent. Only dissolved oxygen returned to its 
upstream (Site 3) concentration at the 



Table 2. 



Water chemistry determinations for the sewage effluent and diluted 
sewage in Blanco River side channel. 



Parameter (mg 1~1) 



Sewage effluent 



Side channel 
(diluted sewage) 



BOD 5 

Chlorine 

Dissolved oxygen 

NH4+NH3-N 

pH (units) 

Potassium 

Total alkalinity 

Total dissolved 

phosphate-phosphorus 



44.20 
0.80 
6.40 

18.40 
7.65 

33.00 

276.00 

3.30 



9.00 
0.00 
7.55 
6.80 
7.85 
7.80 
240.00 
1.70 



Vol. 91 (1) 



October 30, 1979 



THE NAUTILUS 125 



Table 3. 



Water chemistry determinations for the Blanco River. 









Twelve month average (range) 


Parameter (mg 1 ) 


Above 
(Site 3) 


Below 
(Sewage Plant) 


Downstreeim 
(Site 6) 


BOD 5 


1.2 
(0.9 - 2.2) 


1.8 
(1.0 - 5.0) 


1.6 
(1.0 - 2.6) 


Dissolved oxygen 


8.97 
(6.75 - 10.42) 


8.79 
(6.88 - 10.35) 


8.97 
(7.42 - 10.37) 


NH'!;+NH,-N 
4 3 


0.03 
(0.01 - 0.05) 


0.09 
(0.01 - 0.27) 


0.06 
(0.01 - 0.14) 


Organic - N 


0.24 
(0.09 - 0.36) 


0.38 
(0.09 - 0.63) 


0.36 
(0.08 - 0.49) 


Potassium 


2.06 
(1.70 - 2.70) 


2.27 
(1.85 - 2.85) 


2.48 
(1.85 - 2.78) 


pH (units) 


7.88 
(7.74 - 8.02) 


7.87 
(7.74 - 8.02) 


7.89 
(7.75 - 8.02) 


Total alkalinity 


193 OO 
(165 - 212) 


197.00 
(170 - 224) 


196.00 

(170 - 224) 


Total dissolved 

phosphate-phosphorus 


0.12 
(0.04 - 0.26) 


0.24 
(0.05 - 0.49) 


0.22 
(0.04 - 0.72) 



downstream station (Site 6). The nutrient levels 
of ammonia-N best indicated the enrichment of 
the sewage effluent upon the Blanco River (Table 
3). 

Tolerance Tests 

The laboratory tolerance tests were chosen 
because they measured parameters that were 
potentially toxic to freshwater mussels and which 
may result from organic enrichment. Since the 
laboratory tests lasted only seven days, highly 
stressful conditions were needed for definitive 
results. Nevertheless, the concentrations chosen 
were environmentally realistic. During the labor- 
atory tolerance tests, it was frequently observed 
that the more tolerant species had their shells 
tightly shut, while the least tolerant species 
usually continued siphoning or had their mantles 
exposed. 

Tlie exotic asiatic clam (Corhicula manilensis) 
demonstrated greatest survival to low oxygen 
conditions (Table 4). The native mussels, Amxlon- 
ta imhecillis and ToXDlasmn texaserms, also had 
relatively high survival capacities to low 
dissolved oxygen, whereas Cyrtonauu^ tampicoen- 
sLs and Amblema p. plicata had the lowest sur- 
vival tolerances. Amblema p. plicata had a 



significantly lower survival tolerance to low 
dissolved oxygen (Table 5). Although the four 
other species exhibited large differences in their 
survival capacities (Table 4), they were not 
significantly different at 95% confidence limits 
(Tables). 

TdXdlasma texxmensi^ demonstrated the highest 
survival capacity during the aerated high am- 
monia tests (Table 6), whereas Arwdonta im- 
beciUis and Amblema p. plicata had the lowest 
tolerance to high ammonia concentrations. Due to 
their frequent gaping, snapping of valves and ex- 
trusion of glochidia when gravid, Anodnnta im- 
becillis appeared to be the most stressed species. 
All species frequently secreted mucous at the 
beginning of the aerated ammonia experiments. 
The interspecific survival capacities were not 
statistically different at 95% confidence limits for 
the mussels in high ammonia (Table 5). 

In the combination high ammonia— low oxygen 
tolerance tests, Corbicula manilensis again 
demonstrated the highest survivorship (Table 7). 
No apparent synergistic effects were detected in 
the combination high ammonia— low dissolved ox- 
ygen tests. Interspecifically, Amblema p. plicata 
had significantly lower survival tolerance and 
Corhicvla manilensis had significantly higher 



126 THE NAUTILUS 



October 30. 1979 



Vol. 94 (4) 



tolerance as compared to mast of the other 
species (Table 5). 

Survival of the mussels, e.xcept Corbinda 
manilensnn in the combination low o.xygen— high 
ammonia tests, appeared to be related to the 
mussel's tolerance to one of the two most .stress- 
ful parameters. Intraspecfic suiTival capacities in 
the laboratory tolerance tests were not signifi- 
cantly different at the 95% confidence limit. 

The tolerance tests in diluted sewage again 
demonstrated that Corbicula manilensis had 
significantly higher survival capacities (Table 5 
and 8). Amhlema p. plicutu had significantly 
lower tolerance to the diluted sewage, while 
Criitonnkui tnmpicoemis and Anodonta imbecillis 
exhibited intermediate survival capacities that 
were not significantly different from each other. 

The levels of potential toxicants in the sewage 
side channel are given in Table 2. Ammonia and 
{wssible potassium were found at ptjtentially 
lethal concentrations. However, the measured 
daylight and nocturnal oxygen levels did not ap- 
pear near the lethal range nor potentially 
stressful during the tolerance tests. Although low- 
oxygen levels may not have been present in the 
sewage side channel (Table 2), the relative 
tolerance of the mussels was comparable to their 
.survival capacities in the combination low o.xygen 
—high ammonia tolerance tests (Tables .5, 7 and 
8). 



Quantitative Samples 

Quantitative sampling sites were chosen in 
areas with similar substrates at mid-stream loca- 
tions in both the slow and fast moving waters. 
The substrate composition shown in Table 9 is 
from faster moving waters (0.3 - 1.5 m deep), but 
even at the sampling stations in the slower mov- 
ing waters (1 - 4 m deep) more than 90% of the 
substrate was composed of fine gravel or larger. 
All quantitative sampling sites were located in 
areas containing relatively high populations of 
freshwater mussels. Therefore, data presented in 
Table 10 is representative of the more dense 
mus.sel populations of the Blanco River. Marked 
differences were noted in the number of species 
and the populations of mussels above and below 
the point of entry of the sewage effluent (Table 
10). Initially during the study period large 
numbers of mussels were found in the river im- 
mediately below the sewage effluent (Fig. 1). At 
the end of the study period in July, 1977, very 
few mussels were found alive at this site. The 
large numbers of mussels initially found in the 
uppermost portion of the enriched study area 
may have been transported by floods from a large 
bed of mussels found just upstream at Site 3 (Fig. 
1). 

Of the native species. Amblema p. plicata and 
Qumlnda petrina were the most abundant. The 
asiatic clam (Corhicida manilensis) was not 



Table 4. Percentage survival in low oxygen concentrations (0-0.5 mg O^ 1 ■'■) . 



Species (Number used) 



55 hr 



110 hr 



165 hr 



Amblema p. plicata 



Anodonta imbecillis 



Corbicula manilensis 



Cyrtonaias tampicoensis 



Toxolasma texasensis (8 



88 



100 



100 



88 



100 



88 



89 



62 



88 



75 



89 



38 



62 



Vol. m (I) 



October 30, 1979 



THE NAUTILUS 127 



Table 5. 



Statistical analyses of tolerance tests (SNK) for interspecific mean 
survival times. 



Species 



Low 0-) 



Tolerance Test 



High NH3 



Low O2 + High NH3 



Diluted Sewage 



1) Amblema p. 
plicata 



2) Anodonta 

irabeci His 



-S(all) 



+3(1) 



3) Corbicula 

manilensis +S(1) 



4) Cyrtonaias 

tampicoensis +S(1) 

5) Toxolasma 

texasensis +S(1) 



NS 



NS 



NS 



NS 



NS 



-S(3,4,5) 


-S(all) 


-3(3) 


+ 3(1) 
-3(3) 


+3(1,2,5) 


+S(all) 


+S(1) 
-S(3) 


+3(1) 
-S(3) 


+3(1) 
-S(3) 





3 = Significantly different at 95% confidence interval (-3 = lower; +3 = higher). 
NS = Not significantly different at 95% confidence interval. 



noticeably present in the study area in the spring 
or summer of 1976. However, immature Corbinda 
manilensis were found about 7 km upstream of 
the study area in the spring of 1976. Immature 
specimens were first evident in the study area in 
the spring of 1977. Corbicula manilensis was 
found in much higher concentrations above the 
sewage effluent than given in Table 9. Densities 
of up to 50 m"^ of small individuals were found in 
the uncontaminated headwaters of the Blanco 
River side channel (Fig. 1). The highest numbers 
of Corbicula manilensis occurred in sand-fine 
gravel substrates. No living specimens of Cor- 
bicula manilensis were found below the entrance 
of the sewage effluent in the Blanco River. 

DISCUSSION 

From the previous records of Strecker (1931) 
all of the species collected in the present study, 
except the exotic asiatic clam (Corbicula manilen- 
sis), have been present in the Guadalupe River 
drainage for many years. Since Lainpsilis 
bracteata is still present in the Guadalupe and 
San Antonio River drainages, and Quadrula 
aurea (Lea, 1859) is also present in the 
Guadalupe River drainage, the continued ex- 
istence of these species may not be threatened. 



Athearn (1970) has considered both Lampsilis 
bracteata and Quadrula aurea as rare and en- 
dangered in central Texas. 

Some species of mussels are limited in their 
distribution by the type of stream bottom. For 
example, mussels of the genus Anodonta and Lep- 
todea fragilis were only rarely found in rocky 
substrates (Murray and Leonard, 1962). In the 
Blanco River Anodonta imbecillis and other 
species with relatively thin, light weight shells 
did not occur in swift waters with coarse 
substrates. This might be due, in part, to their 
physical displacement and/or destruction by the 
shearing forces in faster waters. 

Considering the rapid dissemination and 
population growth of Corbicula manilensis. their 
abundance in the upper half of the study area in 
1977 was not suprising even though none were 
noted in 1976. Gardner et al. (1976) observed that 
the population of Corbicula manilensis in the 
Altamaha River (Georgia) increased from a 
minimum of 0/m^ in 1971 to a maximum of 
10,000/m^ in 1974. Corbicula manilensis main- 
tains a distinctive reproductive advantage over 
the usually dioecious, slow growing, glochidial- 
producing native freshwater mussels. Corbicida is 



128 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



monoecious, incubates its free-living larvae and is 
sexually mature in less than one year (Gardner 
et al. 1976). 

The physicochemical parameters measured 
from July, 1976, to June, 1977, for the Blanco 
River were similar to those found from other 
parts of the Guadalupe River drainage (Hannan 
et al. 1973; Young et al. 1972). The large in- 
creases of ammonia-N (300%) below the point of 
entrance of the sewage effluent into the river 
suggested organic enrichment of the stream. Am- 
monia values often are a good index of changes in 
trophic status of streams that have been in- 
fluenced by excessive enrichment by organic 
wastes (Ellis 1937). 

Although pronounced changes in the water 
chemistry were found below the point of entrance 
of sewage effluent into the river, none of the 
parameters measured were at concentrations 
known to be toxic or harmful to freshwater 
mussels. Upon consideration of the sources of 
waste entering the secondary treatment plant, ex- 
cessive pollution by heavy metals or pesticides 
was not likely. The lack of measurable flow in 
the Blanco River as reported by the Kyle gauging 
station during previous dry periods (U.S.G.S. 
1976), however, could increase the levels of poten- 
tial toxicants to concentrations equal to or 
greater than the levels found in the diluted 
sewage side channel. When the Blanco River 
stops flowing, as it does every few years, the 



sewage is not diluted when it enters the river 
and is then the primary source of water below 
the sewage plant. 

The levels of ammonia-N, potassium and noc- 
turnal dissolved oxygen could be potential 
hazards for the mussels during such low flow 
periods. Imlay (1973) found potassium levels of 11 
ppm to be toxic in 36-52 days to 90% of the 
freshwater mussels tested, and for long term sur- 
vival. Imlay (1973) postulated that potassium 
levels should be no higher than 4 to 10 mg T'. It 
is doubtful that potassium would be a problem in 
the Blanco River. In contrast, it is well known 
that nocturnal dissolved oxygen deficiencies also 
can be critical in determining stream distribution 
of organisms (Gaufin and Tarzwell 1952). 
Organically rich pools or slow moving waters in 
the Blanco River might experience extreme fluc- 
tuation in O2 concentration, especially at the 
mud-water interface. Cx)nsidering the levels of 
potential toxicants (ammonia, low O2 and 
potassium) in the Blanco River, as demonstrated 
by their values in the diluted sewage side chan- 
nel, ammonia is probably the most lethal stressor 
to mussels during the low flow periods. 

The depletion of dissolved oxygen that results 
from sewage enrichment has been proposed as the 
principle stressor influencing molluscan survival 
(Ingram 1957). Ellis (1937) stated that juvenile 
mussels are very sensitive to low oxygen concen- 
trations and that adults usually become quiescent 



Table 6. 



Percentage survival in high ammonia (5 mg NH +NH -N) 

4 3 



Species (Number used) 



55 hr 



110 hr 



165 hr 



Amblema £. plicata 



( 9) 



78 



56 



33 



Anodonta imbecillis ( 9) 



100 



67 



56 



Corbicula manilensis (14) 



100 



95 



62 



Cyrtonaias tampicoensis (10) 



100 



100 



70 



Toxolasma texasensis (10) 



100 



80 



80 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 129 



Table 7. Percentage survival in low oxygen and high anunonia 

i - 
3 



(0-0.5 rag O2 1~ + 5 mg NH>NH^-N) 



Species (Number Used) 



55 hr 



110 hr 



165 hr 



Arnbleraa p. plicata 



( 8) 



100 



25 



Anodonta imbecillis 



(12) 



60 



40 



Corbicula manilensis 



(16) 



100 



93 



93 



Cyrtonaias tampicoensis (10) 



80 



60 



Toxolasma texasensis 



(10) 



90 



20 



when oxygen levels are at or below 20% satura- 
tion. However, mussels generally are more 
tolerant of low O2 levels than freshwater fishes. 
One of the more tolerant of the freshwater fishes, 
the carp, survives only a short time in water con- 
taining 0.71 mg O2 1'. In contrast, in the low O2 
tolerance tests (0 - 0.5 mg O2 1"') about 53% of 
the mussels tested in this study survived for 
seven days (Table 4). 

During the laboratory tolerance tests, the 
mussels that did not have their valves closed for 
extended periods were more senstive to stressors 
(NH3 and/or low O2). A similar conclusion was 
made by Ellis (1937), who reported that if 
mussels failed to respond by shell closure to low 



dissolved oxygen, then they were more vulnerable 
to destruction by pollution. Extended gaping of 
the valves usually precluded death. In the 
laboratory tolerance tests when a mussel began 
to gap its valves, death would usually follow 
within several hours. 

Mussels that were stressed usually siphoned 
less and had their valves closed for longer periods 
than the non-stressed specimens. Badman (1975) 
noted that under hypoxic conditions, Elliptio 
dilatatus and Pleurobema cocdneum increased 
periods of valve closure and reduced filtration 
rates, whereas in contrast, Allen (1923) reported 
widening of the siphons and mantles to pass more 
water through the mussel (increased respiration) 



Table 8. Percentage survival to diluted sewage in the Blanco River side channel. 



Species (Number Used) 



7 days 14 days 



21 days 



28 days 



Amblema p. plicata 



(16) 



12 



Anodonta imbecillis (10) 



70 



20 



Corbicula manilensis (20) 



100 



65 



50 



50 



Cyrtonaias tampicoensis (11) 



64 



27 



130 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



Table 9. Substrate composition of two typical collecting areas. 





Type 


U.S. Series No. 


Size (mm) 


Percent 
Upstream 


Composition 

Downstream 


Boulder 


- 


256 


- 




- 


Cobble 


- 


64-256 


49.10 




20.90 


Coarse gravel 


- 


32-64 


11.50 




26.10 


Medium gravel 


- 


8-32 


24.60 




36.50 


Fine gravel 


8 


2-8 


12.30 




13.00 


Very coarse sand 


18 


1-2 


1.80 




1.50 


Coarse sand 


40 


0.5-1 


0.62 




1.54 


Medium sand 


60 


0.25-0.5 


0.02 




0.32 


Fine sand 


120 


0.125-0.25 


0.04 




0.10 



as a result of low oxygen levels. The various 
species may respond differently to environmental 
stressors. 

The mussels most tolerant of low dissolved ox- 
ygen were collected from standing or slow mov- 
ing waters. For example, the more tolerant 
Anndonta imbecillvi and Toxolasma texasensw 
were taken from ponds or reservoirs, while the 
more sensitive Amblema p. piicata was collected 
in the fast moving waters of the Blanco River. At 
least for some mussels, tolerance to low dissolved 
oxygen levels might be correlated with distribu- 
tion. 

Insufficient dissolved oxygen was suggested by 
Isom (1971) as a cause for the decline of the 
endemic mussel fauna in Fort Loudoun Reser- 
voir, Tennessee. Organic enrichment of the reser- 
voir was apparently the causative agent. 

Perhaps even the rapid colonization of aquatic 
habitats by Corhkula manilensis is due to their 
tolerance to stressful physicochemical conditions 
as well as their reproductive capabilities. Hable 
(1970) found that Corhkula was resistant to low 
oxygen levels and that the presence of Anodonta 
imheciltia and Corhicula manilensi.'i in Fort Lou- 
doun Reservoir, when they had not been 



previously detected in the Tennessee River, may 
have been -due not only to their fecundity, but 
also to their relative high tolerance to low 
dissolved oxygen. As with Corbicida maniletisis, 
Anodonta imbedllis is monoecious and has 
glochidia that may develop to maturity without a 
living host (Murray and Leonard 1962). 

The lack of significant differences in survival 
capacities to elevated ammonia levels 
demonstrated that of the mussels tested, all are 
relatively sensitive to ammonia. In aerated 
aquaria, where the pH of the testing waters 
varied from 7.8 to 8.2 and was similar to the pH 
of the Blanco River, concentrations of 5 mg 
ammonia-N 1' were lethal to 40% of the 
mussels tested in seven days (Table 6). The am- 
monium ion (NH,) is not very toxic, but molec- 
ular NHj is highly toxic. The proportion of 
ammonia to ammonium ions greatly increases 
with decreasing hydrogen ion concentrations, and 
as reported by Ellis (1937), pH is an important 
factor in the toxicity of ammonium compounds to 
aquatic animals. For instance, Ellis (1937) found 
that for daphnia and gammarids, the toxicity of 
ammonium compounds increased 200% or more 
as pH increased from 7.4 to 8.0. 



Vol. 94 (4) 



October 30. 1979 



THE NAUTILUS 131 



With concentrations of 6.8 mg ammonia-N 1' 
(pH 7.85), the diluted sewage in the side channel 
contained ammonium levels which exceeded the 
experimental ammonium levels utilized in the 
laboratory. The concentrations of 18.4 mg 
ammonia-N 1"' in the sewage effluent would pre- 
sent potentially lethal levels if the effluent com- 
posed 20% or more of the total stream flow. Such 
conditions would exist in the Blanco River if the 
flow was reduced to about 0.1 m^ sec"' which 
would be 15 times lower than the minimum flow 
(1.5m ' sec-') found for 1976-1977. 

Over long periods, much lower concentrations 
of ammonia may be detrimental to mussels. Ellis 
(1937) found that 1.5 mg ammonia 1' was the 
maximal concentration not indicative of organic 
pollution. In streams mth pH values ranging 
from 7.4 to 8.5, ammonia levels of 2.5 mg 1' 
would tend to be detrimental to many freshwater 
animals (Ellis 1937). Levels of ammonia-N prob- 
ably should be kept below 1 ppm in all streams 
containing mussel populations. 

Mussels are more sensitive to ammonia than 
the common goldfish, Carassiiis auratus. which 
Ellis (1937) listed as tolerant to 10 ppm am- 
monium carbonate (pH 7.7) for more than four 
days. Conversely, and as mentioned earlier, 



physiologically mussels are less sensitive to low 
dissolved oxygen levels than goldfish. However, a 
mussel's chances for survival when unfavorable 
conditions occur is reduced by their lack of 
mobility and confinement to the substratum. 
Ma.ximum allowable ammonia-N levels in a 
fishery is 0.02 mg l"' (Wellingham, 1973; NAS 
and NAE, 1972). 

In general, laboratory tolerance tests 
demonstrated that Corbicula manilensis was the 
least, and Amblema p. plicata the most sensitive 
of the mussels (Table 5). However, not all 
Amblema can be called "sensitive". On the basis 
of their high densities in "conditionally polluted 
areas", Richardson (1928) postulated a species of 
Amblema (A. mtiplicata) to be the least sensitive 
of the mussels sampled in the Illinois River. 

Since specimens for this study were collected 
by handpicking, the youngest age classes of 
mussels were not observed. Mussels less than 
three years of age are commonly overlooked when 
handpicking (Van Cleave 1940). No information, 
therefore, was collected on mussel reproduction 
when exposed to the stressors or on larval 
tolerances. It is likely that individuals of the 
same species, but of different ages, have 
dissimilar tolerances to stream pollutants (Ellis 



Table 10. Quantitative samples of the freshwater mussels of the Blanco River. 



Species 



Upstream (ic/m^) 



Site 1 Site 2 



Site 3 



Downstream (x/m2) 



Site 5 Site 6 



Amblema p. 
plicata 



2.7 



6.8 



5.7 



0.0 



0.1 



Corbicula 

manilensis 



1.6 



0.0 



1.6 



0.0 



0.0 



Cyrtonaias 

tampicoensis 



0.0 



0.6 



0.0 



0.0 



0.0 



Lamps ills a. 
anodontoides 



0.1 



0.0 



0.0 



0.0 



0.0 



Lamps ills 
bracteata 



0.1 



0.0 



0.1 



0.0 



0.0 



Quadrula 
petrina 



0.2 



0.5 



1.3 



0.0 



0.1 



132 THE NAUTILUS 



October 30. 1979 



Vol.94 (4) 



1937). Pollution tolerance data, therefore, must be 
viewed with caution. 

Based upon the results of this study the sug- 
gestion by Weber (1970) that Corbicnla is less 
tolerant than Anodonta imbecillis to organic 
pollution may be incorrect. 

Due to the intolerance of mussels to diluted 
sewage in the side channel and because the 
substrate and other physical factors below the ef- 
fluent of the treatment plant of San Marcos are 
basically similar to those factors upstream, the 
decreased number of mussels downstream was 
probably due to organic enrichment (Fig. 10). The 
severity of sewage pollution would increase 
tremendously during low or no flow periods. No 
other explanation is available at present to ac- 
count for the disproportionate lack of mussels 
below the entrance of the sewage effluent in the 
Blanco River. 

Simons and Reed (1975) noted that the 
molluscan segment (mostly mussels) of the ben- 
thic community represented a more sensitive por- 
tion of the macrobenthos than did most insects in 
the North Anna River, Virginia. The point of full 
"biological recovery" of the North Anna River 
was assumed to have been where the mussel 
populations had been reestablished (Simons and 
Reed 1975). 

As suggested by Ingram (1957) and from data 
presented here, mussels may have value as in- 
dicators of nonpolluted waters because their 
presence typically indicates high dissolved oxygen 
and associated chemical and physical conditions. 
For determination of the severity of water pollu- 
tion reduced numbers of "clean water" species 
which were formerly present in the stream may 
be more important than an abundance of known 
pollution resistant forms (Richardson 1928). 

The following concluding remarks can be made 
from the tolerance tests and field studies. 

(1) Low dissolved oxygen levels (0 - 0.5 mg Oj 
1') proved lethal to 47% of the mussels tested in 
seven days. 

(2) Levels of 5 mg NHVNHj 1"' (pH 7.S to 
8.0 were lethal to 40% of the mussels tested in 
seven days. 

(3) Even in waters with dissolved oxygen levels 
not indicative of pollution, ammonia levels can be 
lethal to mussels. 

(4) Corbicula manilensis is generally more 



tolerant and Amblema p. pHcata less tolerant 
than the other mussels tested to stressors 
associated with sewage enrichment. 

(5) Even though the physicochemical 
parameters did not indicate stressful conditions 
on the days sampled, mussels of the Blanco River 
seemed to have been adversely affected by enrich- 
ment from the secondary sewage treatment plant 
of San Marcos. Fewer mussels were found 
downstream from the sewage plant than 
upstream. 

LITERATURE CITED 

Allen. W. R. 192.3. Studies of the biology of freshwater 
mussels. IT. The nature and degree of response to certain 
physical and chemical stimuli. Ohm Jmirnal <;/ Science 
23(2):.57-82. 

American Public Health Association. 1975. Standard methods 
for the examination of water and wastewater. 14th ed., 
Amer. Publ. Health Assn. Inc., Washington, D.C. 1193 pp. 

Atheam. H. D. 1970. Sj-mposium: rare and endangered 
mollusks. MalacoUym 10(1):28-31. 

Badman. David G. 197.5. Filtration of neutral red by 
freshwater clams in aerobic and h>TX)xic conditions. Comp. 
Biichem. Phyifiol. 51(4):741-744. 

Bedford. J. W.. E E. Roelofe. M. H. Zabik. 1968. The 
freshwater mussel as a biological monitor of pesticide con- 
centrations in a lotic environment. Limmit. (keanogr. 
13:118-126. 

Burch, J. B. 1973. Freshwater Unionacean clams (Mollusca: 
Pelecv-poda) of North America. U. S. Environmental Protec- 
tion Agency, Biota of freshwater ecosystems. Identification 
Manual No. 11:1-176. 

Burkhalter. R. E. and C. M. Kaya. 1977. Elffects of prolonged 
exposure to ammonia on fertilized eggs and sac fr>' of Rain- 
bow Trout (Salmii gairdneri). TYans. Am. Fijsh. Soc. 
106(5):470-475. 

Butler, P. A. 1965. Biological problems in water pollution. U. 
S. Dept. of Health, Education and Welfare. Public Health 
Service Publ. No. 999-vvt5-25. pp. 1-92. 

Charles. .J. R. 1964. Effects of oilfield brines. Proceedings of 
the Eighteenth Annual Conference. Southeastern Associa- 
tion of Game and Fish Commissioners. 

Churchill. E. P.. .Jr. 1916. The absorption of nutriment from 
solution by freshwater mussels. ./ Exp. ZnoL 21:40:i-430. 

Ellis, M. M. 19.37. Detection and measurement of stream pollu- 
tion, p. 129-185. In L. E. Keup, et ai.. [eds.]. Biology of water 
pollution. 1967. USDl. FWPCA, ann.,Ohio. 

Fuller. S. L. H. 1974. Clams and mussels (Mollusca: Bivalvia). 
p. 21.5-27.3. In C. W. Hart, .Jr., and S. L. H. Fuller [eds.]. 
Piillutiiiti ecdttyy of freshwater in vertebrate a. .Academic 
Press, New York. 

Gardner. .J. A.. .Jr., et al. 1976. The invasion of the asiatic 
clam in the AJtamaha River, Georgia. TV Nautihis 
90(3):117-125. 

Gaufin, A. R. and C. M. Tarzwell. 19.52. Aquatic invertebrates 
as indicators of stream pollution. Public Health Reports 
67(1):57-&1. 



Vol. M (4) 



October 30, 1979 



THE NAUTILUS laS 



Habel, M. L. 1970. Oxygen consumption, temperature 
tolerance, filtration rate of introduced asiatic clam Cor- 
hicula manilensi.t from the Tennessee River, M. S. Thesis, 
Auburn University. .Auburn. Alabama. 66 pp. 

Hannan. H. H.. W. C. Young, J. J. Mayhew. 1973. Nitrogen 
and phosphorus in a stretch of the Guadalupe River, Te.xas, 
with five main stream impoundments. Hydrobwlngia 
43(3):419441. 

Holme, N. A. and A. D. McInt>Te. 1971. Methods for the study 
of marine benthos. IBP Handbook No. 16:30-.51. 

Imlay, M. H. 1973. Effects of potassium on survival and 
distribution of freshwater mussels. Malacologia 12(1): 97-113. 

Ingram, W. M. 1957. Use and value of biological indicators of 
pollution: freshwater clams and snails, p. 94-135. In C. M. 
Tarzwell [ed.]. Biological problems in water pollution. 
USDHEW, PHS, R. A. Taft Sanitary Engineering Center. 
Cinn.,Ohio. 

Isom, B. G. 1971. Mussel fauna found in Fort Loudoun Reser- 
voir Tennessee River, Knox County, Tennessee, in 
December, 1970. Malacological Reiriew 4:127-130. 

Mathis, B. J. and T. F. Cummings. 1973. Selected metals in 
sediments, water and biota in the Illinois River. Water 
Pnll Contr. Fed. 45(7):1.57.3-1583. 

Murray. H. D. and A. B. Leonard. 1962. Handbook of unionid 
mussels in Kansas. Univ. of Kansas, Lawrence KA. 184 pp. 

Murray, H. D. 1968. Checklist of freshwater and land mollusks 
of Texas. Sterkiana 30:2S42. 

National Academy of Sciences and National Academy of 
Engineering. 1972. Water quality criteria 1972. U. S. Gov. 
Print. Off. Washington. 

Neel, J. K. and W. R Allen. 19&1. The mussel fauna of the 
Upper Cumberland Basin before its impoundment. 
Malacohgia 1 :4274.59. 

Richardson, R E. 1928. The bottom fauna of the middle Il- 
linois River, 191-3-1925. Its distribution, abundance, valua- 
tion and index value in the study of stream pollution. ///. 
State Natur. Hjst. 17:.387475. 



Simmons, G. M., .Jr. and J. R. Reed, Jr. 1973. Mussels as in- 
dicators of biological recovery zone. Water Poll. Contr. Fed. 
45(12): 2480-2493. 

Simpson, C. T. 1914. A descriptive catalogue of the naiades or 
pearly freshwater mussels. Detroit. 1540 pp. 

Strecker, J. K. 1931. The distribution of the naiades or pearly 

freshwater mussels of Texas. Spec Bull. Baylor Univ. 
Museum. No. 2:1-71. 

U. S. Geological Survey. 1976. Water resources data for Texas. 
National Technical Information Service. Springfield, Va. pp. 
242-245. 

Van Cleave, H. J. 1940. Ten years of observation on a 
freshwater mussel population. Ecology 21 (3):.363-369. 

Weber, C. I. [ed.] 1973. Biological field and laboratory 
methods for measuring the quality of surface waters and ef- 
fluents. U. S. Environmental Protection Agency. Cinn., 
Ohio. pp. 26-38. 

Wilber, C. G. 1969. The biological aspects of water pollution. 
Charles C. Thomas Publ., Springfield, Illinois, pp. 276-279. 

Williams, J. C. 1969. Mussel fishery investigation Tennessee, 
Ohio and Green Rivers. Final Rep., Kentucky Dept. of Fish 
and Wildlife Resources and Murray State University Biol. 
Station. Murray, Ky. pp. 1-107. 

Willingham, T. 1973. Ammonia toxicity and its removal from 
wastewaters. Environ. Prot. Agency (U.S.A.), Reg. VIII, 
Eng. Section, Enforcement Div. 

Young, W. C, H. R Hannan, J. W. Tatum. 1972. The 
physicochemical limnology of a stretch of the Guadalupe 
River, Texas, with five main stream impoundments. 
HydrobHilogiaiO{3y.2°R-3\9. 



Zar, J. H. 1974. Biostatistical analysis. 
Englewood Cliffs, N.J. 622pp. 



Prentice-Hall, 



ALLOCATION OF "MARGINELLA " CORDEROI CARCELLES, 1953 
TO A NEW GENUS IN THE VOLUTE SUBFAMILY ODONTOCYMBIOLINAE 

(GASTROPODA) 

Miguel A. Klappenbach 

Museo Nacional de Historia Natural 
Montevideo, Uruguay 



Marginella corderoi was described and il- 
lustrated by Carcelles (1953:10, pi. III. fig. 17, 18) 
as coming from places located in the South 
American Atlantic littoral, at the mouth of the 
Rio de la Plata. The description as well as the il- 
lustrations, left us with a certain doubt about the 



correct allocation of the species in the genus 
Maryiiiella. 

Subsequently we examined the holotype 
(M.A.C.N. "Bernardino Rivadavia" N° 24194) 
coming to the conclusion that what we really had 
was a Volutidae, without being able, though, to 



134 THE NAUTILUS 



October 30. 1979 



Vol.94 (4) 



determine the genus for lack of knowledge of the 
soft parts. Rios (1970:112) also expressed his 
doubts about it, placing the generic name in 
quotation marks and stating that it did not look 
like A Marginella. 

Recently we have obtained on the shore of the 
Brasilian State of Rio Grande Do Sul (a3°17'S 
-.50°34'W Operation CEDIP II, 10-20-72, in a thin 
muddy bottom) some specimens of the above men- 
tioned species with its soft parts (Col. Male. 
M.N.H.N. N° 8809). We then prepared the radula 
and verified that the species belonged to the sub- 
family Odontocymbiolinae (Clench & Turner, 1964: 
170). The radula is formed by a single row of 
rachidian teeth and each one of them is made 
up of a basal plate forming a medium angle (Fig. 
2) from which a long, narrow, curved, hook- 
shaped tricuspid emerges. This characteristic, the 
large protoconch and the proportionally short 
spire, allow us to place this species close to Odan- 
tocymbiola Clench & Turner, 1964. 

Nevertheless, the details of the sculpture, axial- 
ly ribbed, crossed by thinner spiral cords clearly 
separate it from this genus. However, this 
sculpture is a characteristic of Miomelon philip- 
piana (Dall, 1890) type-species of the genus 
Miomelon (Dall, 1907:365). But the latter presents 
a high spire and very small protoconch with a 
rachidian tooth formed by a basal plate, roughly 
rectangular, and no angle in the middle portion 
(Pilsbry & Olsson 1954:pl. 27, fig. 10) (Stuardo & 




FIG. 1. Minicymbiola (new genus) corderoi (Carcelles. lH.'i.l). 
Tj/pe <if Ihe genii.s. PiimtiflM' specimen No. ■U9J,, Malaciilayical 
Collection, Museo Nacional de Hiitoria Natural . Montevideo. 
200km west of Urug-uay in loometers. 



Villarroel, 1974:14.5, fig. 17); these features do not 
agree with the species of Carcelles. 

For the above reasons, we think that it would 
be convenient to establish a new genus for the 
species with the following diagnosis: 

Minicymbiola gen. nnv. 

Type-Species: Manjinelln corderoi Carcelles, 
195-3 

Dicujiiosis: Shell small within the subfamily. 
The largest specimen we know is 28 mm in length 
(N° 11.430 of the Collection Museo Oceanografico 
de Rio Grande, Brazil) and it was obtained in 
Uruguayan waters 3.5°05'S and 52°40'W, 117 m 
in depth. Spire short; protoconch moderately large 
and dome-shaped. Axial sculpture formed by 
rounded ribs crossed by thinner spiral cords. 
Radula with arched basal plate forming an angle 
at its middle part and bearing three long, narrow 
and curved cusps. Periostracum and operculum 
are absent. 

Distribution: At present, represented only by 
the type-species which is found in the South 
American Atlantic from the State of Parana, 
Brazil, in the North. (Rios, 1970:112) to the Pro- 
vincia of Buenos Aires, Republica Argentina, in 
the South. 

Remarks: The subfamily Odontocymbiolinae, 
Clench & Turner, 1964, contains five genera: Odon- 
tocymbiola Clench & Turner, 1964; Miomelon 
Dail, 1907; Tractolira Dall, 1896; Volutoconm 
Crosse. 1871; and now Minicifmbivla. The only 
known living species of Tractolira are from 
Pacific waters, off Central America, in abyssal 
depths. The protoconch forms an apical spur 
that characterizes them easily. 

Vdlutoconiis has four species restricted to 
Australian watei-s. In this genus the protoconch 
bears an apical spur, and other features are pre- 
sent that allow us to separate it from the genera 
known to South American waters (Atlantic or 
Pacific). A second species, represented only by 
the holotype up to now. from a locality between 
the Malvinas Islands and Magailanes, Miomelon 
ticoresbyana Powell, 1951, possibly should be 
removed from this genus when its radula is 
known and placed in Minici/mbiola. Its short 
spire, stump-shaped apex, and its sculpture con- 
sisting of very weak axial lines of growth 
(Weaver & du Pont, 1970: pi. .56, E.F.) similar to 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 135 



the ones found in Odontoritmhiola pescalia Clench 
& Turner, 1964, or in young specimens of Odon- 
tocymhiola magellanica (Gmelin, 1791) indicate 
its affinity with Odontoci/mbiola and separate it 
from Mianielon. 

Finally, we have the genus Odontoci/mbinla 
Clench & Turner, 1964, which contains four 
species living in South American Atlantic waters: 
0. ainericuna (Reeve, 1856), 0. mmiclUtnicn 
(Gmelin, 1791), 0. pescalia Clench & Turner, 1964 
and 0. sHb)i()d()>in (Leach, 1814): the last one was 
included in the genus recently by Weaver & du 
Pont (1970:130) and by Castellanos (1970:2). The 
last three species present a characteristic unit 
that gives homogeneity to the gi"oup. This is not 
the case with 0. americana (Reeve, 1856) also 
considered to be in the genus: but its smaller 
size, smooth e.xterior surface and rather sharp 
nodes separate it from the former ones. We 
should emphasize that Clench & Turner (1964: 
129) stated that the characteristics of the shell of 
0. americana (Reeve, 1856) are closest to the ones 
of AulJcirm vespertilio (Linn^, 17.58) from the 
West Pacific, but the radulae are different, plac- 
ing the species in different subfamilies. 

In short, it appears to be logical to include the 
new genus Minicymbiola in the subfamily Odon- 
tocymbiolinae based on the radular char- 
acteristics. Also it appears as a very distinct 
genus easily separated from Odontocifm^iola by 
its small size and conspicuous a.xial sculpture and 
its spire. It is easily distinguished from Miomdan 
by its short spire, large and stump-shaped apex 
and by the conformation of the basal plate of the 
rachidian tooth. 

The name Minicymbiola cnrderni (Carcelles, 
1953) should not be confused with another volute, 
Ffovocator corderoi Carcelles, 1947, an entirely 
different species. 




FIG. 2. Twd rachidian radulae of Minicymbiola corderoi 
(Carcelles. 195S). from a specimen off Rio Grande Do Sul. 
Brasil. 

LITERATURE CITED 

Castellanos. A. A. de. 1970. Reubicaci(5'n de algunas especies de 

Volutidae del Mar Argentine, Neotropica, 16(49): 1-4, La 

Plata. Argentina. 
Carcelles. A. 19.5.3. Nuevas especies de Gastropodos Marines de 

las Republicas Oriental del Uruguay y Argentina. Com. 

Zool. Mus. Hist. Nat. Montevideo, 4(70): 1-16. pis, 1-.5. 
Clench, W. J. & Turner, R. D. 1964. The Subfamilies 

Volutinae, Zidoninae, Odontocymbiolinae and Calliotectinae 

in the Western Atlantic. Johnsonia, 4(4.3): 129-180. pis. 

80-114. 
Dall, W. H. 1907. A Review of the American Volutidae. 

Smith. Misc. Coll.. 48:341-37.3. 
Pilsbry, H. A. & Olsson. A. A. 19.54. Systems of the Volutidae, 

Bull Amer. Paleont. 35(152):27.5-306. pis. 25-28. 
Rios, E. C. Coastal Brazilian Seashells, 1-255, pis. 1-60. 4 maps. 

Rio Grande. Brazil. 
Stuardo. .J. & Villarroel. M. 1974. On Some Living and Fossil 

Volutes Referred to Miomelon Dall. 1907 and Proscaphella 

von Ihering. 1907, Tlie Veliger. 17(2):139-1.5.5. 21 figs. 
Weaver, C. S. & du Pont, .J. E. 1970. The Living Volutes, 

Monograph Ser. 1. Delaware Mus. Nat. Hist. I-XV. 1-.375, 

pis. 1-79. 



136 THE NAUTILUS 



October 3n. 1979 



Vol. 94 (4) 



LOCALIZED EGG SHELL DISSOLUTION DURING DEVELOPMENT IN 
STENOTREMA LEAI (PULMONATA: POLYGYRIDAE) 

Alex S. Tompa 

Museum of Z<)olop\- 

University of Michigan 

Ann Arbor, Michigan 48109 

ABSTRACT 
As the embryo of Stenotrema leal (Binney) undergoes development, it first dis- 
solves the calcite ai/stnls in the mder part of the egg, not uniformly throughout 
the surface of the egg, but at a local area of the shell. Fiimlly the rest of the egg 
shell calcium crystals are dissolved. This observation is at odds with previous ex- 
pl/ui(tti<i)is of egg shell dissolution only by lowering egg albumen pH. Now it seems 
that some larval organ is specifically applied against the egg shell and causes local 
calcium resorption in one area at a time The two mx>st likely organs which could 
be involved are the embryonic podocyst, which is a modification of the foot, or the 
mouth region. 



Recent work has clearly demonstrated that the 
egg shell of most land snails contains calcium 
carbonate crystals which the embryo utilizes for 
its own calcium needs during development (Tom- 
pa, 1975). Almost all the work pertaining to such 
embryonic calcium utilization has involved eggs 
which are said to be heavily calcified (Tompa, 
1974), i. e., they have a brittle, hard calcium shell. 
In such a system, using the eggs of Strophocheilus 
oblongus, it has been shown that the egg fluid pH 
dramatically decreases and fluid calcium concen- 
tration concomitantly increases during develop- 
ment (Tompa, 1979). Because of this documenta- 
tion, it appeared that all of the egg shell calcium 
must be dissolved at the same rate, equally all 
around the egg, since a pH decrease in the egg 
albumen fluid would cause erosion everywhere 
where it touches the egg shell. The present study 
deals with changes associated with development 
in the partly calcified egg of the land snail 
Stenotrema leai (Binney) (alias monodon (Rac- 
kett)). This study suggests that a pH change in 
the egg albumen is not sufficient by itself to ex- 
plain the differential disappearance of calcite 
crystals in the outer egg layers in partly calcified 
eggs. 

MATERIALS AND METHODS 

Stenotrema leai snails were collected within 
the city limits of Ann Arbor, Michigan. They 
were brought into the laboratory, fed on a diet of 
carrots, chalk and filter paper, and were found to 
mate and breed successfully. Containers were 



checked for eggs every day; when found, they 
were immediately isolated and placed inside a 
small glass Petri dish containing ash-free filter 
paper moistened with deionized water. Qose-up 
photographs were periodically made of the 
developing eggs. 

RESULTS 

A total of ten clutches were examined. The 
number of eggs per clutch was 2.06 ± 1.06, with 
each clutch ranging in size from 1-4 eggs. The 
average size of the eggs laid was 2.28 ± 0.14 X 
2.29 ± .18 mm. Approximate time of hatching at 
20°C was two weeks. The pictures illustrated in 
Figure 1 were taken from eggs of the same 
clutch, in increasing order of age, so that Figure 
1 is a newly deposited egg, while Figure 4 is 
within a few days of hatching. 

The most striking aspect of this developmental 
sequence is that the egg crystals are not dissolved 
uniformly around the embryo. Instead, certain 
areas of the shell are preferentially dissolved, 
often completely, before other parts of the calcite 
layer were involved. Figure 2 is an especially 
striking example of this phenomenon, where one 
small area of the egg shell has been completely 
denuded of calcite crystals while the rest seem 
intact. As indicated in Figure 4, most eggs lose 
their opacity by the time of hatching, and become 
transparent from loss of the crystal layers in the 
outer egg shell. This same type of localized calcite 
dissolution has been subsequently observed with 



Vol.94 (4) 



October 30. 1979 



THE NAUTILUS 137 



^^^HHlTj 


^^^^^^^^^^ 


^^H^^^M 





FIGS. 1-4 Illustrate the appearance of prugresmvely older eggs 
of Stenotrema leai during incubation at room temperature. 
1, is a freshly deposited egg: 2, is older by several days and 
shows a single prnnounced area of crystal dissolution: 3, is 
older still, with a more extensive area of calcium, carbonate 
erosion. 4, is an egg only a few days from the time of 
hatching: here the embryo occupies most of the egg and only 
a very snudl amount of caleite crystal material is left. This. 
too, will disappear before final hatching. White scale bar in 
the upper right comer indicates 0.5 mm. All four eggs are 
from the same clutch: i is the maximum number of eggs 
found per chdch for this species in the laboratory. 

eggs of other partly calcified eggs, such as those 
of the pulmonates, Varohadra yeppoonensis from 
Australia and Helicodiscus parallelus from the 
northern United States. 



act site of caleite disappearance. Especially in 
the earlier parts of development, the egg is 
opaque and the embryo is not visible. Presently, 
the best guess is that either 1) the embryonic foot 
organ called the podocyst (see Gather and Tompa, 
1972) is applied to this area to dissolve calcium 
carbonate, or that 2) the mouth and its secretions 
are directly responsible. We know that im- 
mediately post-hatching, the neonate consumes 
all of the egg shell remnants available and may 
even rasp on the shells of other nearby eggs 
(numerous sources; personal observations with 
such snails as Helix, Stenotrema, Anguispira, 
etc.). On the other hand, it is also known that the 
podocyst, an embryonic organ modified from the 
foot, functions in taking up egg albumen (Gather 
and Tompa, 1972) and indeed it may have a 
calcium resorbing function as well, such as in the 
avian embryo's chorioallantois (Terepka et ai, 
1969). This is all the more likely since the 
podocyst is often seen directly appressed to the 
inner egg shell surface for long periods of time. 
The podocyst is often so large in later develop- 
ment that it makes direct contact with 50% or 
more of the inner surface area of the egg shell. 
Therefore, either the podocyst or the larval 
mouth area takes part in egg shell caleite resorp- 
tion. The embryo, of course, needs this calcium to 
build its first whorls of the body shell, the pro- 
toconch, so that it has a hard shell by the time of 
hatching (Tompa, 1975). No doubt, such a hard 
shell, into which the neonate can withdraw, has a 
direct and immediate selective advantage where 
micropredators abound; the calcific egg shell is 
dissolved, then re-precipitated by the embryo as 
aragonite body shell crystals. 



DISGUSSION 

The cause of such specific and localized caleite 
dissolution is not clear and conflicts with the 
previously held ideas that a general erosion of 
the egg shell crystals occurs during development. 
The present study suggests that while there may 
be a moderate degree of general crystal dissolu- 
tion during development, limited areas are 
preferentially attacked and rapidly dissolved. 

It has not been possible to associate the jux- 
taposition of any embryonic organ with the ex- 



LITERATURE GITED 

Gather. J. and A. Tompa 1972. The podocy-st in pulmonale 
evolution. jV/a/ar. Rev. 5:1-3. 

Terepka. A., M. Stewart and N. Merkel 1969. Transport func- 
tions of the chick chorioallantoic membrane. II. Active 
calcium transport, in vitro. Expt. Cell Res. 58:107-117. 

Tompa. A. 1974. The structure of calcareous snail eggs. Malac. 
flpr. 7:49-50. 

197.5. Embryonic use of egg shell calcium in a 

gastropod. Nature 255:232-33. 

1979. pH and calcium concentration changes in a 



molluscan egg during development. Experientia. 35:812-813. 



138 THE NAUTILUS October 30. 1979 Vol.94 (1) 

GASTROPODS AS INDICATORS OF TROPHIC LAKE STAGES 

Arthur H. Clarke 

Smithsonian Institution 
Washington. D.C. 20560 

ABSTRACT 

Field data associated with the 91 species and subspecies of boreal and arctic 
North American freshwater gastropods were analyzed. Most species and subspecies 
are eurytopic, but a few are entirely, or nearly, restricted to lakes of particular 
trophic levels. These are: Valvata sincera sincera Say for oligotrophic lakes. 
Fossaria decampi fStreng) and Stagnicola catascopium (Say) for oligotrophic and 
mesotrophic lakes, and Amnicola limosa (Say). L\Tnnaea stagnalis juguiaris (Say), 
and Planurbula armigera (Say) for eutrophic lakes. Physa integra Haldeman is fre- 
quently associated unth mesotrophic lakes but also occurs in other habitats. The 
indicator species are illustrated and briefly described. 



The literature dealing with gastropods as in- 
dicators of water quality, especially in regard to 
water pollution, has been recently reviewed by 
Hannan (1974). That paper includes a survey of 
existing knowledge (including new observations) 
about the tolerances of many species of 
gastropods to extremes of pH, alkalinity, total 
CO2. dissolved O2, and temperature, and to in- 
dustrial wastes and pesticides. The fundamental 
value of this approach is unquestioned, although 
as that author has also pointed out, most 
moUusks have broad tolerances for environmental 
perturbations and "almost every common species 
has been found in polluted environments" (loc cit. 
p. 302.) 

The present study seeks to assess the possible 
utility of freshwater gastropods, not as pollution 
indicators, but as indicators of progressive 
ti'ophic lake stages. It is based on the literature 
and on about 2000 freshwater field collections 
and associated observations made since 1950 
throughout cool-temperate, boreal, and arctic 
North America (Clarke, 1973. 1980). Although the 
field experience has been fairly extensive, in most 
instances the trophic character of a lake was 
judged solely on qualitative observations. The 
conclusions presented here must therefore be con- 
sidered provisional. Most freshwater species listed 
here are eurytopic or wide-ranging in habitat 
tolerance, but others are restricted to lakes in 
various stages of development. 

Of course mollusks have biological require- 
ments which affect their utility as indicator 
organisms. Since most pulmonates are ranfined to 



shallow water where access to the atmosphere is 
possible, they commonly occur near the water 
line or among emergent vegetation. Many, 
however, are apparently able to capture and use 
the oxygen released by plants during photosyn- 
thesis and in some the pulmonary cavity is filled 
with water and functions as a branchium or gill. 
Such adapted pulmonates, like prosobranchs. can 
thrive in the deep profundal zone of lakes. 
Although some species have been found in water 
with very low oxygen saturation levels (Harman. 
1974), it is unlikely that any species is able to 
live for long periods in regions which periodically 
undergo prolonged and dra.stic reductions in 
dissolved oxygen, such as within the hypolimnia 
of many eutrophic lakes. Eggs of gastropods, in 
fact, ai'e even more susceptible to low oxygen 
values. 

Table 1 represents a preliminary' attempt to 
tabulate the relative abundance, regional geo- 
graphical distribution, and kinds of water bodies 
inhabited by the freshwater gastropods of 
northern North America. The species list is 
thought to be complete for Canada and virtually 
so for Alaska. Nearly all of the species found in 
New England and the states bordering Canada 
are also included, and some can serve as laketype 
indicators. 

The attributes which a species should possess 
to be useful as an indicator of lake-stages are: 
wide geographical distribution, comparative 
abundance, relative stenotopy, and ease of iden- 
tification. The table demonstrates that only a few 
of the 91 species and subspecies listed combine all 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 139 



Relative Abundance, Approxlnace Distributions, and Uaual ^j 
HablcaCB □( Che Freshwacer Gaattopoda of northern North Aseclca 



Lynnaea atkaeoals Dall 
Valvata sincera slncera 



Valvata perdeprcsaa Walker 



Foaaarla decaapl (Streng) 



Stagnlcola caataacoplua 
catascopluB (Say) 



SCagDlcola keonlcottl Bakei 



Phyaa pioplnqua Tryon 

Phyaa Jennesal Jenneaal 

Dan 

Physa hecerostcopha (Say) 

Somatogyrus subglobosus 
(Say) 

Phyaa Integra Kaldeman 

Clnclonacla Cincinnati ens I 
(Anthony) 

Physa gyrina latchfocdl 
(Baker) 

Hellsona corpulentun 
verallionense Baker 

Valvata placlnalla (Wilier) 

GonlabBBis llvescens 
(Henke) 

Llthoglyphua vlreos (Lea) 

BullBus teotaculatus (L) 

Foasaria exigua (Lea) 

Physa Jennesst atheaml 
Clarke 

Physa coluablana Henphlll 
Physa lordl Balrd 



lellsooa campanulatuit 

caatpanuLatun (Say) 



Stagnlcols elodea (Say) 
Stagnicola proslaa (Lea) 
Valvata slncera ontarlenal 



Paeudosucclnla colunella 
(Say) 



Bullmea aegasotsa (Say) 



Lymaca scagnalls Jugularts 
(Say) 



Stagnicola arctlca (Lea) 
(^raulua deflectus (Say) 



Hcllaoaa trlvolvla trlvolvl 
(Say) 



H of 55' IE o! 9M' 



DISTHIBUTION 



OLICOTR KESOTR EUTROPK VERMAL 



XXX 
XXX 



XXX 
XXX 



XXX 
XXX 



CAT 

: A T B » P 



XXX 
XXX 



XXX 
XXX 



XXX 
XXX 



XXX 



I'hy.o gyrina gyrlna Say 
CytauLus parvus (Say) 



I Rafli 



Juga pllclfera (Lea) 

Canpetoma declsuB (Say) 

Vtvlparus georglanus (Lea) 

Clpongopaludlna chlnensls 
(c:ray) 

Harstonla decepca (Baker) 

Lyogyrus granun (Say) 

Anilcola walkert Pllsbry 

Amlcola llaosa (Say) 



Foasaria truncatula 

(MUller) 

Radix aurlculsrla (L) 
Radix peregra (Wller) 
Acella haldemanl (Blnney) 

Armlger crista <L) 

(Dall) 
KeneCus Cooper 1 Baker 
Plsnorbula amlgera (Say) 
LaoDia Crlvolvia bioneyl 



Phyaa concolor Haldeoan 
Physa hordacea Lea 
Phyaa nutcalll Lea 
Laevapez fuacus (Adams) 
FerrlsBla fragllls (Tryoo) 
Fossarla madlcells (Say) 
naea bulltaoldes 

BakerllynmMa dalll (Sakfr) 
Stagnicola reflexa (Say) 

Gyraulls vennlcularls 

(Could) 



W of 95* E of 9i' OLICOTR KESOTR EUTROPH VERHAJ, 



Fronenetus tnbll 

( Cockerel 1) 


Icatell 


Physa Jennesal sklnoeri 

Taylor 


Apleia hypnoruB 


(L) 


Planorbula caope 


atrin 



DISTRIBUTION 



T B H P 
T B H P 



Stagnicola caperata (Say) 



Stagnicola aoatancDals 

(Baker) 

Phyaa Johnaoni Clench 
Ferrlaala rivularla (Sav) 
Lonx nuttalli (Haldeman) 
Fomatlopsls lapldarla (Say) 
Fossarla parva (Lea) 



T B C 
T B C 



XXX 

XXX 
XXX 
XXX 

XXX 



XXX 

XXX 



XXX 
XXX 



XXX 
XXX 
XXX 
XXX 
XXX 
XXX 



XXX 
XXX 



XXX 
XXX 



XXX 
XXX 



id springs 
streams and sp -Ings 



ant hlbioi 
aa{ hlbloi 



(1) 



Abbreviations. Abumlance: C, abundant or cccraon: R, uncommon op rar«: It recently 
introduced (relative abundance unstable). Distribution: A, arctic; T, artic-bore*! 
transition zooej B, boreal forest; H, Mstem mountain regioni P, prairie and parkland 
region; G, Great Lakes-St. Lawrence forest region. Habitat: X, frequent occurreneej 
X, infrequent occurrence. 



140 THE NAUTILUS 



a-tober 30, 1979 



Vol.91 (1) 



Apex 



[Vnultimatc 



Bod\- whorl 




OwCTlip 



FIG. 1. Part.'! of a gastropod ahell. 

of these attributes. These are: (for oligotrophic, or 
early stage, lakes)' Valvata sincera sincera Say; 
(for both oligotrophic and mesotrophic lakes) 
Fossaria decampi (Streng) and Stagnicola 
catascopium (Say); and (for eutrophic, or old, ad- 
vanced stage, lakes) Amnicola limosa (Say), Lipn- 
naea stagnalis jugularis (Say), and Planorbula ar- 
migera (Say), among others. In southern Canada 
Physa Integra Haldeman occurs most frequently 
in mesotrophic lakes and is therefore of some use 
as an indicator also, but it is not entirely 
restricted to such habitats. It is also worthwhile 
to note that Stagnicola caperata (Say) and 
Gyraulus circumstriatus (Tryon) are confined to 
vernal, or temporary, water bodies and that 
Aplexa hypnorum also ordinarily occurs only in 
vernal habitats. 

The lake-stage indicator species are illustrated 
in Fig. 2 and briefly described below. This is for 
the benefit of those who are not familiar with 
mollusks but who wish to use them for lake 
classification. The structural features mentioned 
are illustrated in Figure 1. However, positive 
identification can only be achieved by considera- 
tion of all species which are similar to the in- 
dicator species. For additional references consult 
especially Baker (1928), Clarke (1973, 1980). Har- 
man & Berg (1971), La Rocque (1966-70) and 
Taylor (1975). 

Prosobranchia 

Valvata sincera sincera Say (Valvatidae) (Fig. 
2, A) is one of about six boreal North American 
species and subspecies of Valvata. It is up to 3.2 
mm high and 5 mm wide, with four rounded 

' Lymnnra nthaetifix. although known only from oligotrophic 
lakes, is restricted to Alaska and extreme northwestern 
Canada. 



whorls sculptured with widely-spaced coilabral 
threads (8 or fewer per mm), and a round oper- 
culum with about 6 turns. It is similar to 
Valvata .'iincera helicoidm Dall but that sub- 
species is more northern, is larger (up to 7 mm 
wide) and has finer, more crowded, coilabral 
threads (11 or more per mm). 

Amnicola limosa (Say) (Hydrobiidae) (Fig. 2, B) 
is one of eight boreal North American species in 
the family. Most northern hydrobiids are less 
than 6 mm high, are higher than wide, and 
possess an ovate aperture and an ear-shaped 
operculum with fewer than three turns. (One 
species, Lyogyrus granum, has a round. 




FIG. 2. Trophic take-stage indicator .spprics of gaxtropixlx. A, 
Valvata sincera sincera (USNM .i.ma,. width i.ll mm/: B, 
Amnicola limosa (USNM 2?109<). height J,.J mm): C, Physa In- 
tegra (NMC J.i?J,. height ll.ti mm): D, Fossaria decampi 
(NMC S97(ili. height 11.2 mm): E, Lymnaea stagnalis jugularis 
(NMC Ii7i9. Iieight 61.1 mm): F, Stagnicola catascopium 
catascopium (NMC 2197. height 1S.7 mm): G, J, Planorbula 
armigera (NMC 29S19. mdth 6..i mm): H, P. armigera show- 
ing position of internal "teeth" (NMC ■i9:lJ,5. width J,.7 mm). 
.Abbreviations: USNM. Smith.tonian In.ttitution: NMC. Na- 
t iomil Mu.<!eums of Canada. 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 141 



multispiral operculum). A. limnsa is up to 4 1/2 
mm high, 3 1/3 mm wide, with 4 1/2 convex 
whorls, and has a blunt (but not truncated) spire. 
It is often abundant on lily pads and other 
vegetation. .4. limom occurs throughout the 
eastern two-thirds of the United States and 
Canada south of the tree-line. 

Pulmonata 

Fosmria decarnpi (Streng) (Lymnaeidae) (Plate 
1, figure D). The Lymnaeidae is a large family 
(26 Canadian species and subspecies) char- 
acterized by shells which are rather thin, high- 
spired, and dextral (i.e. coiled clockwise when 
viewed from above) and by the absence of an 
operculum. Nearly all Fosmria (6 species in 
Canada) are less than 12 mm long at the adult 
stage (5-6 whorls) and most are less than 8 mm. 
F decarnpi (normally 4-8 mm long and about half 
as wide) may be recognized by its shouldered 
whorls, laterally flattened body whorl, elevated 
and reflected inner lip, and aperture which is 
narrowly arched above and broadly rounded 
below. It occurs in the Great Lakes-St. Lawrence 
drainage and north and west throughout the 
boreal forest region, principally in large lakes. 

Stagnicola catascopium catascopium (Say) 
(Lymnaeidae) (Plate 1. figure F). Most Stagnicola 
(10 species and subspecies in Canada) are medium- 
sized (10-35 mm), variable, and have relatively 
strong shells. S. catascopium catascopimn shows 
unusually great interpopulation variability. Most 
specimens are between 13 and 25 mm long, about 
2/3 as wide, with a rather heavy shell, low spire, 
broad aperture, inflated whorls, deep suture, and 
thickened inner lip. It occurs across North 
America (except in northern British Columbia, 
Yukon Territory, and Alaska) south to about 
40° north latitude. 

Li/mnaea stagnalis jugularis Say (Lymnaeidae) 
(Plate 1, figure E) (formerly L. stagnalis appressa 
Say) is larger (often 60 mm long), with height 
about double the width, up to 7 1/2 whorls, and 
thin-shelled. It has a long, narrow spire with con- 
cave sides and flatly rounded whorls and a bul- 
bous body whorl. This common subspecies lives 
throughout nearly all of boreal and temperate 
Canada and the northern United States e.xcept 
for the extreme eastern portion, i.e. it is absent 



from most of New England, the Canadian Mari- 
time Provinces, and noithern Quelxx'. 

Phym Integra Haldeman (Physidae) (Plate 1, 
figure C). The Physidae (about 16 Canadian 
species and subspecies) have shells which are thin 
in most species, high-spired, and sinistral, i.e. 
coiled counterclockwise when viewed from above. 
They all lack an operculum and are small to 
medium-sized (7-26 mm high). P. integra is up 
about 15 mm high, 9 mm wide, with five whorls, 
and the shell is thicker and heavier than that of 
other northern species of Physa. The aperture is 
thickened within by a white ridge and many 
specimens have several whiteish collabral bands 
representing thickened lips formed during 
previous growth stages. 

Planorbula armigera Say (Planorbidae) (Plate 
1, figure G-J). The Planorbidae (about 21 Cana- 
dian species and subspecies) have shells which are 
nearly all flatly-coiled, with the body whorl in 
about the same plane as the apex, lack an oper- 
culum, and may be small to quite large (3-32 mm 
in shell width). P. armigera is medium sized 
(about 8 mm wide, 3 mm high, 5 whorls) and has 
one (rarely two) set of 5, well-developed "teeth" 
well within the aperture In most specimens these 
teeth may be seen by looking into the aperture 
but in some specimens they are visible only by 
use of transmitted light (as a dark, thickened 
area) or by chipping back about 1/4 of the body 
whorl. Only one other northern planorbid, the 
larger western species P. campestiis (Dawson), 
has apertural teeth but each set contains 6 teeth 
and they occur only in juveniles. P. armigera 
lives throughout eastern and central North 
America from Georgia and Louisiana to New 
Brunswick, northern Ontario, and the vicinity of 
Great Slave Lake in Canada's Northwest Ter- 
ritories. 



ACKNOWLEDGMENTS 
C. 0. Berg and R. S. Houbrick read the 
manuscript and provided u.seful suggestions, Ms. 
Cathy Lamb assisted in the laboratory, and Ms. 
Valerie Fulford prepared the diagrammatic 
drawing. The photographs were provided through 
the courtesy of the Smithsonian Institution and 
the National Museums of Canada. I am grateful 
for all of this assistance. 



142 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



REFERENCES 

Baker, F. C. 1928. The freshwater Mollusca of Wisconsin. Part 
1. Gastropoda. Wiscorusin Academy of Science. Arts, and 
Ij-Aters. pp. i-.\x + 1-.507, plates 1-28. 

Clarke, A. H. 1973. The freshwater molluscs of the Canadian 
Interior Btisin. Malacotoyia 13:1-509. 

1980. The freshwater MoUuscs of Canada Na- 
tional Museums of Canada. Ottawa (in press). 

Harman, W. N. 1974. Snails (Mollusca :Gastropoda) m C. W. 
Hart. Jr. and S. L. H. Fuller (Eds.). Pollution Ecology of 
Freshwater Invertebrates. Academic Press, New York, N.Y., 
389 pages. 



Harman, W. N. and C. 0. Bei^. 1971. The freshwater snails of 
Central New York. Search Agriculture. Entomnlogy (Ithaca) 
2. Agricultural E^xperiment Station, Cornell University, 
Ithaca, NY, pp. 1-68. 

Taylor, D. W. 1975. Index and bibliography of Lake Cenozoic 
freshwater Mollusca of Western North America. Claude W. 
Hibbard Memorial Volume 1, Papers on PaJeontolngy. No. 
10. Museum of Paleontology, University of Michigan, Ann 
Arbor, 384 pages. 

LaRocque, Aurele. 1966-70. Pleistocene Mollusca of Ohio. BulL 
Dept. Natural Resources, Ohio 62(M):l-800. 



A NEW SPECIES OF AMNICOLA FROM AN ARKANSAS CAVE 

(HYDROBIIDAE) 

Leslie Hubricht 

4026 a5th Street 
Meridian, Mississippi 39301 

ABSTRACT 

A blind cave snail, Amnicola cora, is described from Independence Co., Arkansas. 



Amnicola cora, new species 

Figs. 1-3 

Description: Shell small, broadly conic, wider 
than high, thin, subhyaline, pale-yellow; whorls 
3.3, well-rounded the last whorl lightly appressed 
to the preceding whorl, sutures very deep, 
nuclear whorl slightly raised; umbilicus open, 
about one-fifth the diameter of the shell; aper- 
ture nearly round, peristome continuous, barely 
attached to the preceding whorl, lip thin, col- 
umellar margin not reflected or bent; sculpture 
of many fine spiral lines, operculum comeus, 
multispiral, with about 5 whorls. 

Animal white and blind, without any trace of 
eyes; verge bifid, rather stout; central tooth of 
the radula with 11 denticles on the reflection, one 
moderately large mesocone and 5 ectocones on 
each side; lateral tooth with 11 denticles, one 
moderately large mesocone, 3 entocones, and 7 ec- 
tocones; marginal teeth with numerous small 
denticles. 

Height 1.6 mm, diameter 2.0 mm, aperture 
height 1.0 mm, aperture width 0.9 mm, umbilicus 
diameter 0.4 mm, 3.3 whorls. Holotype. 

Distribution: ARKANSAS: Independence Coun- 
ty: .stream in Foushee Case, 3 miles west of Locust 
Grove (Type Locality) (Norman & Jean Young- 



steadt; Leslie Hubricht, collectors) holotype 193762, 
and paratypes 193763, Field Museum of Natural 
History, other paratypes 47584, 47585, collection of 
the author. 

Remarks: Amnicola cora is most closely related 
to A. stygia Hubricht from cave streams in Perry 
Co., Missouri. It differs in being smaller, with 
more slowly expanding whorls, the shell is not as 
fragile, and the operculum is multispiral rather 
than paucispiral. It is named for the Attic god- 
dess, Cora, Queen of Hades. 






2mm 



FIG. 1-3. Amnicola cora Hubricht. holotinw. Fh-nwings courtesy 
iif Elisabeth A. Leibman. Field Museum of Nat uraJ History. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 143 



THE BEHAVIOR OF THREE SYMPATRIC SPECIES OF CREPIDULA 

(GASTROPODA: PROSOBRANCHIA) FROM THE ATLANTIC, WITH 

IMPLICATIONS FOR EVOLUTIONARY ECOLOGY 

K. Elaine Hoagland 

Department of Biology 

Lehigh University 
Bethlehem, Pa. 18015 

ABSTRACT 

In the course of a stiuiy of reproductive energetics, behavioral observations were 
made on Crepi'dula fomicata (Linnaeus), C. plana Say, and C. convexa Say. 
Althoiigh C. convexa is intertidal, C. fomicata and C. plana rarely are. C. fornicata 
orients itself on convex, exposed surfaces mth the anterior shell margin upward, if 
possible. C. plana is photonegative. C. fomicata and C. convexa juveniles appear at 
staggered intervals during the .summer in New England. 

When brooding eggs, females of all three species are sedentary. However, all but 
the highly convex or tunsted individ^ials are capable of some movement. C. convexa 
is the most mobile. Only C. fomicata /orws stacks of more than 3 individuals. 

Brooding is energetically costly for Crepidula,' both brood abortion and brood 
cannibalism occur. Eggs can also be delayed in hatching. Newly-hatched C. convexa 
graze using the radxda; filter-feeding is probably not efficient at that stage. 

These behavioral patterns are discussed in terms of their survival advantages 
and niche differences of the three sympatric species. 



There are three species of Crepidula found 
commonly along the eastem coast of the United 
States: C. fomicata (Linnaeus), C. convexa Say, 
and C. plana Say. The three share several generic 
characters of an ecological nature: they are 
primarily sedentary as adults, they must copulate 
in order to reproduce, they are protandrous, and 
they acquire food via filtration of water through 
the gills. Species differences include maximum 
size, shell convexity, shell muscle scar patterns, 
substrate preferences, and whether or not there is 
a planktonic larval stage (Hoagland, 1977b). The 
species can be collected together at many 
localities, including Woods Hole, Massachusetts. 

In the course of a comparative study of the 
reproductive energetics of the three species 
(Hoagland, 1975), behavioral and physiological 
differences were identified that give each species 
unique niche dimensions (Hoagland, 1978; 1979). 
Tiis paper adds further observations on orienta- 
tion behavior, brood care, and feeding in 
Crepidula. After discussing each set of observa- 
tions in turn, I will interpret the findings in the 
context of niche theory and evolutionary adapta- 



tions for the survival of individuals of each 
species. 

STUDY SITES, METHODS 

Individuals of all three species were observed 
in shallow water (less than 1 m) on shell and 
stone substrate resting on mud or sand bottom, 
at Vineyard Haven (Martha's Vineyard) and 
Woods Hole, Massachusetts. Some C. fornicata and 
C. plana were found attached to live horseshoe 
crabs (Limidus polyphemus). Many C. plana and 
C. convexa were on gastropod shells occupied by 
hermit crabs, while C. convexa was abundant on 
live Littorina littorea. C. fomicata was also 
observed on stones in tide pools at Nahant, 
Massachusetts, and on Mytilus edulis attached to 
docks at Tiverton, Rhode Island. 

Some specimens and their substrates were 
marked in the field by notching the shell and 
painting numbers on the substrate. Laboratory 
observations were made on specimens taken from 
the Woods Hole and Martha's Vineyard popula- 
tions. Live specimens still attached to their 
original substrates, or made to attach to watch 



144 THP] NAUTILUS 



Octobers 1979 



Vol.94 (4) 



glasses, were maintained in flowing sea water 
tables at the Woods Hole Oceanographic Institu- 
tion. The temperature was not controlled. 

RESULTS: OBSERVATIONS 

Microhahitat 

Many ecologists describe Crepidula as inter- 
tidal. C. convexa occurs on shells of Littonun lit- 
torea and Uyanassu obsoleta, snails that frequent- 
ly exist intertidally. C. convexa may be found 
with a bone-dry shell, tightly affixed to an equal- 
ly dry living snail, during the hottest summer 
days. Yet C. convexa has been dredged from a 
depth of 212 meters (Abbott, 1974). 

However, C. fiyniicata and C. plana are uncom- 
mon above the mean low tide line. In Nahant, C. 
fomicata is found in upper tide pools, but only 
occasionally are specimens found out of water. In 
Woods Hole, the only specimens of C. fomicata or 
r. plana found out of water in three years of 
study were those deposited ashore by storms or 
by the buoyant alga, Codium fragile, which at- 
taches to the shells of C. fomicata and floats the 
snails to the intertidal zone. Those C. fn-mcata 
and C. plana that attach to the undersides of 
horseshoe crabs or inside hermitcrab-occupied 
shells also find their way into the intertidal zone, 
but remain in a moist environment. 

None of the Crepidula are commonly found on 
hard substrate in the rocky intertidal zone; this 
high energy environment is apparently not suited 
to their mode of life, which is much closer to the 
oyster than to either the limpet or the mussel. 
The preferred substrate of C. fomicata is a con- 
vex surface, not highly irregular. Specimens are 
rarely found on large boulders, but are common 
on fist-sized stones. The bottom sediments are 
usually mud rather than sand; the latter in- 
dicates an environment that is poor in organic 
material and probably in food for filter feeders. 
C. fornirata is known for forming large stacks, 
one animal atop the other (Figure 1). Occupying 
such a convex surface, a C. fomicata individual 
would be exposed to greater currents and less 
sedimentation than if it were located on a con- 
cave surface. 

In the laboratory, young specimens of C. for- 
ninitd placed inside of finger bowls invariably 
climb up and over the edge of the bowl, to the 




FIG. 1. A Mfifk of Crepidula fomicata in life position. Sexes 
(if the indimlualx are indicated. I = intermediate. 

convex exterior. The final orientation is nearly 
always as shovm in Figure 2. The animal sits at 
an angle to the top of the bowl, with its anterior 
shell margin directed upward, near or flush with 
the rim of the bowl. Faeces and pseudofaeces are 
releiised from the anterior shell margin. Mobile 
('. fiirnmiln also tend to move to the part of the 
tank with the most rapid water flow. 

C. convexa has no preference for convex or con- 
cave surfaces, nor does it show precise orienta- 
tion. It forms male-female pairs, but not stacks. 
It attaches to eelgrass blades as easily as to shells, 
bottles, or porcelain (Hoagland, 1977a). 

C. plana prefers dark places and concave or 
flat surfaces, such as underneath rocks or inside 
large empty shells. It forms clusters of several 
males and juveniles on one female, but not 




FIG. 2. Preferred orientation of Crepidula fornicata on the 
iiutxide of a ylaxa fingerhowl. The anterior maiyin touches the 
nm of the hold. Die entire bowl wm submeryed in sea miter. 



Vol.94 (1) 



October 30, 1979 



THE NAUTILUS 145 



stacks. In the laboratory, C. plana juveniles 
display a photonegative response. Natural con- 
cave surfaces tend to be inner surfaces, so it is 
not clear if C. plana is selecting darkness or con- 
cavity or both. 

All three species are sometimes found on the 
same piece of substrate, such as a stone or a dead 
shell. C. plana occupies the under- or inside of 
such a substrate, but the microhabitats of C. for- 
nicata and C. convexa cannot be so easily 
distinguished. In Woods Hole in the years 
1972-1974, the summer reproductive periods of C. 
foniicata and C. convexa did not coincide. C. for- 
nicata spat settled in early June, followed by a 
"set" of barnacles; then C. convexa juveniles ap- 
peared in early July. Another wave of C. for- 
nicata settled in August, and finally more C. con- 
vexa in early fall. This pattern serves to decrease 
competition among juveniles for substrate. Those 
individuals of both C. fomicata and C. convexa 
that settled intertidally disappeared within a few 
days. This indicates either mortality or removal 
to a less exposed microhabitat. 

Mobility 

The common knowledge among ecologists is 
that Crepidula species are largely sedentary. Yet 
Crepidula must copulate, and the substrates of 
Crepidula are spatially discontinuous; the snails 
cannot survive in the intervening sand or mud. C. 
fonmata and C. plana can disperse during the 
planktonic larval stage, but C. convexa lacks this 
stage. I investigated the mobility of the three 
species, to see how wide is their access to the 
substrate and to each other. 

In the field, C. fomicata and C. plana adults 
are largely sedentary. Of 50 female C. fonmata 
marked in the tidepools of Nahant, 34 remained 
in place two years later. C. plana and C. convexa 
were more difficult to follow because their 
substrates moved. However, C. convexa adults 
were observed to travel within tidepools. Those 
living on eelgrass either had to move or perish, 
because the eelgrass died each winter. The greater 
mobility of ('. c(iinr.m. and its greater propensity 
for attaching to living organisms, means that C. 
convexa is more likely to disperse as an adult 
than either of the other species. However, C. con- 
vexa, like all other Crepidula, is sedentary when 
out of water. 



Laboratory observations confirmed the above 
impressions. Small individuals of all three 
species, including most C. convexa, can maneuver 
over abrupt discontinuities in substrate (e.g., 
from one stone to another), across a silty tank 
bottom, as long as there is a hard bottom under- 
neath. Movement can be assessed by measuring 
trails left on the silty bottom. Adult C. fornicata 
and C. plana grow to fit the curvature of the 
substrate, and have difficulty moving. Highly 
arched or distorted specimens cannot move at all. 
Regardless of species, those brooding young do 
not move. 

Both C. fomicata and C. convexa have a 
tendency to climb up (negative geotropism) and 
out of the water when placed in aquaria. They 
often sit above the water line, where they die. 
This tendency can be reduced by increasing aera- 
tion in the tanks. In fact, several times, young C. 
fomicata established themselves directly on top 
of an air stone. When aeration in the tanks was 
stopped, all but the brooding females and those 
attached to other highly arched shells moved up- 
ward. 

The ability of the three species of Crepidula to 
regain their positions on a substrate, once 
dislodged, is very different. C convexa can re- 
attach within seconds, if both animal and 
substrate are wet. C. convexa has a very active 
and flexible foot, which allows an overturned 
animal to right itself. I have observed C. convexa 
floating upside-down on the surface film of the 
water until reaching the side of the tank, where 
it quickly attached. 

Adult C fomicata and C. plana may take 1 to 
3 hours to attach firmly to a substrate. During 
that time, the specimens are vulnerable to crab 
predation. I demonstrated this vulnerability by 
placing several adult Crepidula loose on top of 
their former substrates, accompanied by 3 crabs, 
in an aquarium. All specimens of Crepidula were 
eaten. 

The difference in ease of attachment between 
species is partly, but not completely, due to size. 
Small C. fomicata and C. plana can attach more 
effectively than larger ones, which often have 
irr^ularly-shaped apertures that can only fit 
against the substrate on which they grew. Still, 
small specimens of C. convexa were more resil- 
ient and active than their counterparts. 



146 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



One cause for mobility in Crepidula is to 
enhance breeding success by ensuring copulation. 
In both field and laboratory, C. convexa and 
C. plana males were seen to wander from one 
female to another, although a single pairing of 
C. convexa in the lab lasted as long as 5 months. 
Some C. fomicata males also wander, but some 
spend their entire lives as males with one stack 
of females. Most biologists have assumed that 
stacking in C. firmicata is related to mating. 
Walne (1956) believed that the tendency to form 
stacks was not related to reproduction, but rather 
to the production of feeding currents. The 
strength of the excurrent flow of faeces and 
pseudofaeces may be augmented by the shape of 
the stack, as Walne supposed. No data exist on 
this point. An analogy might be made to oysters, 
which form clusters that serve to raise the 
animals from a muddy substrate, augmenting 
their ability to filter-feed. Yet in Crepidula, the 
stack is a breeding unit (Hoagland, 1978), and 
probably reduces the vulnerability of males to 
predation by reducing their need to be mobile. 
Because of the close proximity of the right 
anterior portions of the shells of a stack (Figure 
1), the several males at the top can easily 
copulate with the several females at the bottom, 
with eight or more individuals in between. This 
leads to a promiscuous breeding system, as is also 
found in C. convexa and C. plana, but by means 
of an entirely different behavior pattern. 

Brood Care 

All female Crepidula brooding young are com- 
pletely sedentary. Interesting problems for 
ecologists include just how much of a liability 
this is for a brooding female. How much energy 
is expended by a brooding female in caring for 
the eggs? Does brooding affect her own chances 
for survival? 

I observed that females of all three species, but 
especially C. fomicata, often push the young out 
from under the shell when aeration is reduced, 
measurably lowering the oxygen tension in the 
aquarium. The same event occurs when the 
animals are kept in millipore-filtered sea water 
(starvation). In three of eight cases of low oxygen 
and two of six cases of starvation, the females 
died after expelling the eggs. Survival of females 
of equivalent size but not br(x)ding eggs was bet- 



ter in all three experimental situations, but in- 
sufficient data were obtained for statistical 
analysis. The data suggest that there is a cost in- 
volved in brooding, and that a female might abort 
a bnxjd, thereby increasing her longevity. 

Egg masses released by females were kept in 
aerated but unfiltered sea water to see if they 
would hatch. Ciliated protozoans, bacteria, and 
nematodes infested most of the egg masses. If 
some of the eggs become inviable, the entire egg 
mass eventually was lost to the predators. 
However, 2 of 10 ^g masses of C. convexa and 4 
of 20 of C fomicata did hatch. The young were 
normal in appearance. Therefore, release of the 
brood by a dying female could be of benefit to the 
young, especially if they were near hatching. 

The role of the female in larval brooding thus 
appears to be related to oxygenation and cleaning 
of the larvae. Egg maintenance appears to re- 
quire continuous circulation of water. A female 
without eggs reduces its filtration if the water 
contains no food, but one brooding eggs continues 
to filter at a high rate. This is one energ>' cost. 
The brood is maintained in the vicinity of her 
gills, which, in these filter-feeders, create strong 
currents flowing over the egg mass (Werner, 
1951). The presence of the egg mass probably 
reduces the efficiency of the gills as respiratory 
and feeding structures; this is another cost of 
brooding. 

Not only can individuals of Crepidula be in- 
duced to leave their broods, but they can 
sometimes be induced to produce eggs at ab- 
normal seasons. In the laboratory, they can also 
retain broods over winter, but this has not been 
observed in nature, at least in New England 
where reproduction normally occurs only in sum- 
mer. In New England waters, Crepidula do not 
develop broods until the temperature exceeds 10° 
C. 

Specimens of C. fomicata collected at Martha's 
Vineyard in December 1972, were accidently left 
outside a water table, in a finger bowl, sometime 
between January 18 and February 1, 1973. The 
water warmed, and two females produced eggs. 
The females with broods were placed back in the 
water table, where the water temperature was 2 - 
4° C. The egg masses finally hatched on April 1, 
1973, at a temperature of 6° C. Another specimen 
dredged from Buzzard's Bay, at a time 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 147 



unrecorded, spawned in a water table on 
February 13, 1973, when the water temperature 
suddenly rose to 6° C. In the summer of 1972, 25 
female C. fomicata were maintained at 9° C, to 
see if egg production could be delayed. None pro- 
duced eggs at 9° during a three-month period, 
June to August, when C. fomicata is normally 
brooding. 

Specimens taken from Martha's Vineyard in 
November, 1972, contained ripe gonads; 
specimens taken from the same locality in 
January, 1973, had spent gonads, although no 
reproduction was observed in the interim. The 
gonads are probably resorbed during winter 
under natural conditions. 

Another question of interest is how long sperm 
can be stored within the seminal receptacle of 
the female. Coe (1953) claimed that sperm storage 
could last several months to a year. In my 
laboratory, females of C. fomkata known to have 
mated but isolated in early June continued to 
reproduce broods through September, but none 
reproduced the following spring. This may have 
been due to sub-optimal feeding in the 
laboratory. Orton (1952) suggested that an in- 
dividual could store its own sperm while in the 
process of changing sex, thereby functioning as a 
self-fertilizing hermaphrodite, but his speculation 
was based on the circumstantial evidence of find- 
ing isolated females with broods. 

Larval Cannibalism 

It had been thought that Crepidula under nor- 
mal circumstances did not provide the developing 
young mth nurse cells (Fretter and Graham, 
1962, p. 404-405). However, Gallardo (1977) has 
reported nurse cells for Crepidida dilatata, and 
Coe (1942), for C onux. Thorson (1940) said that 
some capsules of C. walshi contained large em- 
bryos, while other embryos in the same capsules 
disintegrated. 

An examination of several hundred broods 
each of C. fomicata and C. convexa within 24 
hours of collection in the field revealed that a 
high percentage (10% of C. fomicata; 23% of C. 
convexa) failed to develop. These embryos broke 
up and were ingested by other embryos once they 
had reached the stage of possessing feeding struc- 
tures. If a normal embryo was artificially rup- 
tured with a fine needle, surrounding larvae 



spinning around within the egg capsule drew 
cells from the damaged embryo into their gullets 
via a self-generated feeding current. Both species 
did this, but C. convexa appeared not to have the 
capability once the larvae had lost the velum. If 
the damaged larva is in the veliger stage, the 
velum is not eaten but persists within the egg 
capsule until the capsule ruptures at hatching. 

This process probably explains the cases I have 
seen in C. convexa where some hatching egg cap- 
sules of a brood contain 8-10 uniform, average 
size young, whereas others contain 2-3 very large 
young. It explains Thorson 's observation as well. 
The size at hatching is more uniform in C. for- 
nicata, which releases its brood in the veliger 
stage. 

Feeding 

When the broods are released, C. convexa 
young immediately begin a benthic existence. In 
the laboratory, I observed one brood of newly 
hatched young moving over a glass substrate 
coated with bacteria and microscopic algae. The 
snails' heads swayed from side to side, clearing 
tracks of microorganisms and debris. Inspection 
under the dissecting microscope showed that the 
odontophores and radulas were working, and 
material was entering the guts of the animals. 
Putnam (1964) reported that C. adunca also uses 
its radula to graze when first emerging from the 
egg capsule. Microscopic examination of the gill 
filaments of newly hatched C. convexa proved 
them to be fewer in number than in adults and 
rather fat and club-shaped. It is doubtful that 
they could function efficiently as filtering devices 
at that stage. This is probably one reason that 
Crepidula retains a large, well-developed if 
unspecialized radula, despite the filter-feeding 
mode. 

Another reason for retention of the radula 
(over evolutionary time) is that it is used to han- 
dle food packaged on the gills (Werner, 1951). I 
have observed adults of C. fomicata to reach 
around and grab mucous balls containing large 
particles rejected by the gills (pseudofaeces), 
which normally exit on the right side of the man- 
tle cavity. Occasionally, these balls are re- 
ingested. This behavioral pattern was observed 
only in closed-system aquaria, where I assume 
food availability was low. 



148 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



DISCUSSION 
Evolutionary Adaptations 

Although cause-and-effect relationships are dif- 
ficult to determine in evolutionary biology, one 
can often guess the survival value of a particular 
behavior or morphological structure. In the case 
of Crepidula. it is clear that individual orienta- 
tion is adaptive. In C. fomicata, it maximizes the 
chances of encountering others of the same 
species and maximizes feeding currents while 
minimizing fouling. In C. plana, an orientation 
opposite to C. fomicata with respect to light 
sacrifices availability of currents, but increases 
protection against large predators such as crabs 
and fish. In C conveia. small size and foot flex- 
ibility allow much greater mobility, an obvious 
advantage in a species without planktonic larvae. 

Brooding costs the female an as-yet undeter- 
mined amount of energy. The expulsion of the 
broods under conditions of stress benefits the 
female by saving energy, and may indirectly 
benefit the offspring, which would die if trapped 
under a dead female. In terms of evolutionary 
theory, this is the optimal strategy for an in- 
dividual that has high risk of juvenile mortality, 
can produce numerous broods over its lifetime, 
and that increases in fecundity with age and size. 
The same strategy occurs in birds that abandon 
the nest under unfavorable conditions. 

The survival advantage of brood cannibalism is 
even more obvious. This system prevents wastage 
pf the energy that the female diverted into 
reproduction. Furthermore, nonviable embryos do 
not remain to decay and contaminate the brood. 
The "nurse cells" are not specially differentiated 
as such, but the effect is the same. Fretter and 
Graham (1962, p. 405) described the situation 
structurally: "In capsules in which embryos are 
not separated from one another but share a com- 
mon supply of albumen, it seems likely that a 
healthy individual will automatically devour 
disintegrating tissues with the albumen which is 
used as f(X)d." In terms of evolution, this is a way 
of increasing offspring size, as an alternative to 
the female adding more yolk to all the eggs. The 
advantage of size to a young Crepidula is not 
known, but by analogy to other organisms, it 
probably provides an edge in survival. 



Niche Theory 

The three species of Crepidula from New 
England are the most divergent, morphologically 
and behaviorally, of those living in the Atlantic 
Oceaa The differences among sympatric species 
in microhabitat, mobility, and orientation 
preferences bring up questions about how they 
divide their resources (Schoener, 1974). Hoagland 
(1976) pointed out that in Crepidula, species with 
morphological and ecological parameters in com- 
mon overlap only in the tropics where there is 
closer species packing. In rigorous environments 
such as the northwestern Atlantic, there are 
found the fewest species, with the greatest mor- 
phological and ecological distance between them. 
Important niche-discriminating parameters were 
identified as substrate type, light preference, 
depth preference, and a size factor, correlated 
with types of life history and types of predators. 

Carpenter (1857) also demonstrated that the 
number of sympatric species of Crepidula, and 
the family Calyptraeidae as a whole, decreases 
dramatically with increasing latitude along the 
west coast of North America. Similarly, in the 
Atlantic, those from the northernmost part of the 
province have the most extreme differences in 
morphology. 

Reproductive isolating mechanisms are an 
alternative to competition as an explanation for 
the observed differences between related species. 
However, the need for such mechanisms should 
increase in the tropics, and instead, this is the 
area with the most similar congeners. I conclude 
that the present distribution of Crepidula in the 
Northwestern Atlantic and the behavioral dif- 
ferences of sympatric species are indicative of 
divergence that occurred long ago and had the 
effect of decreasing competition. 

ACKNOWLEDGMENTS 

I thank P. Ander, G. M. Davis, T Schoener, 
and R. D. Turner for stimulating discussion of 
much of this material. G. Grice provided labora- 
tory space at the Woods Hole Oceanographic 
Institution. G. M. Davis and R. Robertson read and 
commented on the manuscript. This work was 
supported in part by a Gibbs Fellowship from 
Harvard University. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 149 



LITERATURE CITED 

Abbott. R. T. 1974. American SeiuihHIx. Second edition. Van 

Nostrand. New York. 663 pp. 
Carpenter, P. P. 1857. Report on the present state of our 

knowledge with regard to the Moliusca of the west coast of 

North America. Report of the Brit. Assoc, for the Adv. of 

Sci for 1856: 159-368. pis. 6-9. 
Coe, W. R. 1942. The reproductive organs of the prosobranch 

mollusk Crepidula onyi and their transformation during 

the change from male to female phase. Jour, of Morphology 

70: .501-512. 
1953. Influences of association, isolation, and 

nutrition on the sexuality of snails of the genus Crepidida. 

Jour, eiper. ZooL 122: 5-19. 
Fretter, V. and A. Graham. 1962. British Prosobranch 

Molhiscs. their Functional Anatomy and Ecology. Ray 

Society, London, xvi + 755 pp. 
Gallardo. C. S. 1977. Two modes of development in the mor- 

phospecies Crepidula dilatata from Southern Chile. Marine 

B>o/(x/.v 39:241-251. 
Hoagland, K. E. 1975. Reproductive strategies and evolution 

in the genus Crepidula (Gastropoda: Calyptraeidae). Ph.D. 
Diss.. Harvard University. 360pp. 
1976. Patterns of evolution and niche partitioning 

in North American Crepidula (Gastropoda: Calyptraeidae). 

A.M.U. Bull, for 1975:b2-^. 

1977a. A gastropod color polymorphism: one adap- 



. 1977b. Systematic review of fossil and Recent 

Crepidula and discussion of evolution of the Calyptraeidae. 
Malacologia 16:a53420. 

1978. Protandry and the evolution of environ- 
mentally-mediated sex change: a study of the Moliusca. 
M(U(woiogia 17:365-.391. 

. (1979). The behavior and physiology of three 



five strategy of phenotypic variation. Biol. Bull. 152: 
360-372. 



species of Crepidida exposed to a desiccating environment. 

Ms submitted to The Veliyer. 
Orton. J. H. 1952. Protandry with self-fertilization in the 

American slipper limpet Crepidula fomicata. Nature 169: 

279-280. 
Putnam, D. A. 1964. The dispersal of young of the commensal 

gastropod Crepidula adunca from its host Tegula funebralis. 

The W/jger6(Suppl.):63-66. 
Schoener, T. W. 1974. Resource partitioning in ecological com- 
munities. .Sc!>«ff 185:27-.39. 
Thorson, G. 1940. Studies on the egg masses and larval 

development of Gastropoda from the Iranian Gulf. Danish 

sci. Invest. Iran 2:159-238. 
Walne, P. R. 1956. The biology and distribution of the slipper 

limpet Crepidula fomicata in &sex rivers, with notes on 

the distribution of the larger epibenthonic invertebrates. 

Pish. Invest. London Ser. II. 20 (6):l-50. 
Werner, B. 1951. tiber die Bedeutung der Wasserstrom- 

erzeugung und Wasserstromfiltration fur die Nahrungsauf- 

nahme der Ortsgebunden Meeresschnecke Crepidula for- 

nicata L. (Gastropoda: Prosobranchia). Zool. Anz. 146:97- 

113. 



THE OCCURRENCE AND SPREAD OF CORBICULA MANILENSIS 
IN EAST-CENTRAL ALABAMA 

John J. Jenkinson' 

Museum of Zoology 
Ohio State University 
Cblumbus. Ohio 43210 



The introduction and spread of the Asiatic 
Clam, Corhicvla manilensis (Philippi, 1841)^ in 
the United States has been recorded by numerous 
authors (review in Sinclair, 1971; Sickel, 1973; 
Fuller and Powell, 1973; Diaz. 1974; Britten and 
Murphy, 1977). These papers generally include 
the type of substrate in which the animals were 



' Present address: T.V.A.. Forestry Building, Norris, TN 37828. 
' In this paper I am following present usage by considering 
C manilensis (Philippi, 1841) to be the name of the eastern 
North American corbiculid species. Morrison, however, be- 
lieves that the vast majority of these populations are C. leana 
Prime, 1864 (J. P. E. Morrison, pe?-.S((«a/ communication. 1977). 



found; the range of size classes (often used to 
suggest the date of the introduction); some men- 
tion of the problems that this exotic bivalve will 
cause to human uses of the watercourse; and, oc- 
casionally, some hypothesis or comment as to how 
Corbicula might have been introduced into the 
system. Few of these papers detail the extent of 
the newly reported Corbicula population, a fact 
which could indicate a great deal about the in- 
troduction of this animal into the stream and its 
subsequent spread within the system. 

Distributional data about previously unre- 



m THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



ported Corhicula populations were collected while 
studying the distribution patterns of unionids in 
east-central Alabama (Jenkinson, 1973: 1975). 
This study (conducted in 1972 and 1973) involved 
four small stream systems, all of which originate 
in central Lee County, Alabama. Two of these 
streams, Saugahatchee (Saw-ga-hach'-ee) and 
Uphapee (You-fap'-ee) creeks, flow west into the 
Tallapoosa River while the other two streams, 
Halawakee (Hal-a-wok'-ee) and Uchee (Ooch'-ee) 
creeks, flow east into the Chattahoochee River 
(Fig. 1). During the course of this study 2,646 
unionids and 76 voucher specimens of Corhicula 
were ajllected from 47 productive sites on these 
four streams. Additional collections have also 
been made in adjacent small streams and in the 
two rivers. 

Tlie resulting distribution pattern for Cor- 
hicula is illustrated in Figure 1. Corhicula is 
abundant in both the Tallapoosa and Chattahoo- 
chee rivers (although I had not found it in the 
Tallapoosa River in 1968), however, Corhicula is 
essentially absent from the tributary streams. 

Uchee Creek Population 

Two exceptions to this general distribution pat- 



tern were found to exist. One large and apparent- 
ly well-established population of Corhicula was 
located in the lower half of Little Uchee Creek 
and in Uchee Creek only below the mouth of Lit- 
tle Uchee Creek. No Corhicula specimens were 
taken in any other part of this creek system 
although unionids were abundant in all of the 
peiTTianent streams. The farthest upstream collec- 
tion of Corbicula from Little Uchee Creek was 
taken at the base of a rapids and falls that mark 
the transition from Piedmont to Coastal Plain 
substrates. This was also the most upstream site 
where fishermen were noticed. Following the 
hypothesis advanced by Sickel (1973), it would be 
tempting to suggest that Corbicula was in- 
troduced into the Uchee Creek system at this site 
by fishermen. Unfortunately, I have no additional 
evidence to support such a hypothesis. 

A similar distribution pattern for Corbicula 
has been reported from the Mesilla Valley of 
Texas and New Mexico (Metcalf, 1966). In that 
case Corbicula occurred in the main channel of 
West Drain but not in its tributaries or in any 
other adjacent tributary of the Rio Grande River. 
Metcalf suggested that the periodic drying up of 




FIG. 1. The Icnitwn di.itributinn o/ Corbicula manilensis (Philippi. ISil). in eaxt-fentml Alabama. Most recorxk date from 1972 
and 197S: Sauyahaichee Creek records aboxte the mouth of Loblockee Creek date from 12 September 1976. 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 151 



the Rio Grande or some adverse environmental 
factors in the unpopulated drains might account 
for this pattern. Neither of these conditions 
seems to be operating in the Uchee Creek system; 
the larger streams always maintain some min- 
imum flow, and any "adverse environmental fac- 
tors" which might prevent colonization by Cor- 
bicula have not affected the thriving unionid 
populations. 

Saugahatchee Creek Population 

The Uchee Creek population was the only Cnr- 
bicula population known from any of these creek 
systems until October 1973, when John C. Hurd 
collected one dead specimen of Corbicula in 
Saugahatchee Creek. This find was unexpected 
because Hurd had surveyed the aquatic mollusks 
of western Lee County in 1970-1971 and had 
found no living bivalves in the main stream of 
Saugahatchee Creek (Hurd, 1971). Hurd had con- 
cluded that unionids were unable to survive in 
Saugahatchee Creek because this stream carries 
the effluents of a large textile mill and a sewage 
treatment plant. 

In addition to the mill and sewage effluents, 
Saugahatchee Creek also receives water from the 
experimental ponds of Auburn University 
Department of Fisheries and Applied Aquacul- 
ture. During the summer of 1972 a project was 
conducted in some of these ponds to determine if 
Corbicula could be used as a biological filter to 
reduce the plankton levels in commercial catfish 
ponds. At the end of that project the clay bottoms 
of the test ponds were screened in Saugahatchee 
Creek to separate out the Corbicula for counting 
and growth analysis. The dead specimen that 
Hurd collected some distance downstream during 
the following fall might have been an escape or a 
discard from this screening process. Regardless of 
the origin of this specimen, collections made in 
November 1973 indicated that living Corbicula 
did exist in Saugahatchee Creek at that time. 

Starting with the collections made in Novem- 
ber 1973, three sites on Saugahatchee Creek have 
been sampled at approximately 18-month inter- 
vals in an attempt to monitor the status of the 
Corbicula population in this stream. The most 
upstream of these sites is located appro.ximately 
one kilometer above the experimental pond 
discharge and the area where the pond bottoms 



Ikm, upstream Hm- downstream 10km. downstream 




HG. 2. Girbicula ciiUectiim results from three sites an 
Saugahatchee Creek taken over a three-year period. Numbers 
along each ordiimte refer to maximum shell length in 
millimeter's: those along each abscissa refer to numbers of in- 
diiiduals with a given shell length. 

were screened. The midstream site is approx- 
imately one kilometer below the screening site 
and the downstream site is approximately nine 
kilometers further downstream. In addition to be- 
ing visited in November 1973, all three sites were 
collected on 8 March 1975 and on 12 September 
1976. On each occasion a hand seive was used to 
collect Corbicula specimens from sandy areas in 
the substrate. No special effort was made to col- 
lect particular size classes; what was desired was 
an essentially random sample of any living Cor- 
bicula population. The results of these collections 
and the lengths of the living Corbicula specimens 
obtained are shown in Figure 2. 

These collections document that during 
November 1973 a population of relatively small 
(<16mm) Corbicula existed in the creek only at 
the midstream collecting site. In March 1975 
there were no Corbictda at the upstream site, the 
midstream population included some larger in- 
dividuals (>20mm) and the downstream site was 
populated by many small animals (<12mm). By 
September 1976 both the mid- and downstream 
sites included animals with fairly broad ranges of 
shell lengths, the largest still occurring at the 



152 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



midstream site. No. Corbicula specimens had yet 
been found at the upstream site. 

These results strongly suggest that Corhiodn 
was introduced into Saugahatchee Creek within 
one kilometer of, and within a few months of, the 
screening of experimental Corbicula specimens by 
Auburn Fisheries personnel. These results docu- 
ment that Corbicula was able to survive and 
reproduce in a stream which, apparently because 
of pollution, is incapable of sustaining unionid 
populations. So far as the spread of this Cor- 
bicula population is concerned, these results in- 
dicate that an easily detectable population was 
established approximately ten kilometers down- 
stream from the apparent site of introduction in 
more than 12, but less than 28 months. The pop- 
ulation had not spread one kilometer upstream in 
approximately 48 months. 

Current 

The factors responsible for this apparent 
unidirectional colonization pattern are presently 
unknown, however, stream current is one en- 
vironmental factor which could produce this kind 
of effect. According to Sinclair (1971) the North 
American corbiculid species passes through a 
non -swimming, pelagic, veliger larval stage. 
When these larvae are released, they apparently 
cannot swam against the current and all of them 
are carried downstream. The unidirectional effect 
of current alone, therefore, could explain the lack 
of upstream colonization in Saugahatchee Creek. 

The unidirectional effect of current could also 
explain the "unusual" distribution patterns of the 
Corbicula populations in the Uchee Creek system 
and in Mesilla Valley. In both cases, if Corbicula 
had been introduced at an upstream site, the re- 
mainder of the distribution pattern coincides ex- 
actly with the areas where non-swimming plank- 
tonic larvae would be carried by current. In the 
Uchee Creek system current would adequately 
explain why no Corbicula specimens were found 
in Uchee Creek proper above the mouth of Little 
Uchee Creek, although unionids occur in both 
areas. In Mesilla Valley current alone could pre- 
vent an original population in West Drain from 
spreading into any tributary that maintained 
some minimum flow. This same reasoning could 
be used to explain why Corbicula does not occur 
in other east-central Alabama streams even 



though it is abundant in both the Tallapoosa and 
Chattahoochee rivers. 

Although this proposed role of current in di- 
recting the spread of Corbicula populations would 
seem entirely logical and expected, I have found 
no mention of it in the extensive American 
literature concerning Corbicula. Other ideas have 
been advanced, however, to explain the oc- 
currence of this invading organism in certain 
locations. One recently proposed hypothesis is 
that Corbicula sometimes becomes established 
because it is able to out-compete the native 
bivalves in areas that have been disturbed by 
man (Fuller and Imlay, 1976). While this 
hypothesis may fit some situations, especially 
with regard to sphaeriids (e.g. Gardner et al., 
1976), it does not seem to be operating in the 
relatively unaltered Uchee Creek system where 
unionids and Coribula occur together in large 
numbers. In addition, the information presented 
in the abstract by Fuller and Imlay appears to 
support this "current hypothesis" better than the 
"competition hypothesis" they propose. 

Corbicula can no longer be considered to be an 
oddity only worthy of a casual distributional 
note. This organism is now a dominant member 
of many North American freshwater faunas, 
often much more abundant than any other mol- 
lusk. Since we know so little of the biology, 
ecology or taxonomy of this newly-established 
species, every piece of factual information which 
appears in the literature can only serve to in- 
crease our understanding of this animal. In addi- 
tion to the theoretical material presented in this 
paper. I have attempted to detail the present 
distribution pattern of the Corbicula populations 
in east-central Alabama as completely as possi- 
ble. It is my hope that future workers may be 
able to use these data in various ways to increase 
our general understanding of this no-longer alien 
mollusk. 



LITERATURE CITED 

Britton. J. C. and C. E. Murphy. 1977. New records and ecolog- 
ical notes for Cnrbicida manilensis in Texas. The Nautilus 
91:20-23. 

Diaz. R. J. 1974. Asiatic Clam, Corhiaila nmnilensii (Philip- 
pi), in the tidal James River, Virginia. Chesapeake Sci. 
15:118-120. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 153 



Fuller. S. L R and M. J. Imlay. 1976. Spatial comix;lilion 
between Girbirula manilensis (Philippi). the Chinese Clam 
(GirbiculiHae). and freshwater mussels (Unionidae) in the 
Waccamaw River basin of the Carolinas (Mollusca; 
Bivalvia). .4.s.sor. SmdheaMi'rn Bill Bull. 23:6(1. 

Fuller. S. L. H. and C. E. Powell. .Jr. U)73. Range e.xtensions of 
Ciirhicula miiiiileiixis (Philippi) in the Atlantic drainage of 
the United States. Tlie Naidilii.^ 87:.59. 

Gardner, J. A.. Jr., W. R. Woodall, Jr.. A. A. Staats. Jr. and J. 
F. Napoli. 1976. The invasion of the Asiatic Clam {Girhicula 
manilenxix Philippi) in the Altamaha River, Georgia. Vie 
Nautitux9<i:m-125. 

Hurd, J. C. 1971. A survey of the mollusks of the Chewacla 
and Saugahatchee creek drainages in western Lee County, 
Alabama. M. S. Tlirsis. Auburn Univ. 64 pp. 



.Jenkin.son. J. J. 1973. Distribution and Z(joge(]graphy of the 
Unionidae (Mollusca: Bivalvia) in four creek systems in 
east-central Alabama. M. S. Thesix. Auburn Univ. 96 pp. 

197.5. The Fall Line as a barrier to the distribu- 
tion of some unionids (Bivalvia: Unionidae). Amer. 
Mtduadoiiird Union Bull, for 1974::30-31. 

Metcalf, A. L. 1966. Corbicula manUemdx in the Mesilla 
Valley of Texas ajid New Mexico. Vi.e Nautiiius 80:16-20. 

Sickel. .1. B. 1973. A new record of Corbicula manilenxi'; 
(Philippi) in the Southern Atlantic Slope Region of Georgia. 
77ir Av,h/, 7 «.s- 87:11-12. 

Sinclair. R. M. 1971. Annotated bibliography on the exotic 
bivalve Corbiruln in North America, 1900- 1971. Stirkinnn 
43:11-1S. 



DESCRIPTIONS OF SIX NEW FORMS' OF FLORIDA TREE SNAILS, 

LIGUUS F ASCI AW S 



Archie L. Jones 

1.37(1 S.W. 1 1th Street 
Miami, Floi-ida 33131 



In the spring of 1962 I found a group of snail 
hammocks in the southern Everglades of Florida 
that had never before been explored by Liguus 
collectors. One of these supports a polvmorphic 
colony of Liguus fnsciatus (Miiller) that includes 
two new color forms. 

In Pilsbry's (1946) classification of Liguus 
fasciatus, these new forms would be placed in the 
subspecies testudineus Pilsbry. Their closest rela- 
tionship is vfith the form nuitanem. I have called 
these two forms, or morphs, humesi and fmmp- 
tnni. 

Four years earlier (19.58) I had set out with a 
friend in his airboat in search of an especially 
beautiful form, marrjfioratiis, which a Seminole 
Indian, Smallpox Tommy, had shown me. We 
picked up Tommy at his camp three miles north 
of the Tamiami Trail. A lack of communication 
between the Indian and us, or his reluctance to 
take us there, prevented us from finding our 

' Latinized names for color forms. ./» cm (i, varieties, or aberra- 
tions are useful to students of variation, but the.se infrasub- 
specific names, proposed after 1%(). have no nomenclatural 
standing, and hence no priority over properly proposed sjieci- 
fic or subspecific names, according to Articles 1 and 10b of 
the International Code Zool. Nomen. - Editor. 



marmarntus. The group of hammocks to which he 
took us contained instead a new fonn of the 
subspecies testvdineus, namely evergiadesensis. 

The deplorable practice by collectors of 
transplanting the Florida tree snail, Liguiis 
/(isciatia^. to hammocks already populated with 
other Liguus began before the turn of the last 
century and continues to this day. Collectors 
gathered choice specimens of this magnificent 
snail and put them in selected hammocks with 
the e.xpectations of collecting them and their pro- 
geny tefore some other collector did. In 1947 I in- 
terviewed a Mr. Lincoln, a former Florida West 
Coast shell dealer. He was then in his late 
eighties and resided in a rest home in Ft. Myers, 
Florida. He told me that when he was a young 
man he transplanted some Liguus from Long 
Pine Key of the Lower Everglades to Big Pine 
Key in the Lower Florida Keys. Charles Torrey 
Simpson introduced them into his hammock in 
Lemon City (North Miami) so that he could more 
easily observe and study them. "In my bit of 
forest, into which I have carried many specimens 
from elsewhere - - -." 

A great fluriy of transplantation occurred im- 
mediatelv before the establishment of the 



154 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



Everglades National Park in 1947. Collectors 
rushed to the then-to-be Park and removed some 
of the more beautiful varieties and relocated 
them outside the Park in Pinecrest, Collier Coun- 
ty, the East Coast Ridge and the Florida Keys. 
TTiey hid them almost anywhere they thought the 
snails would not be found by other collectors. 
Tliis distribution in no way hurt the Park col- 
onies but the cumulative effect of all the in- 
troductions greatly affected the gene mix of once 
reasonably stable populations, so that now it 
would be next to impossible to work out the 
mystery of the distribution of these snails in 
southern Florida. 

Liginu^ feed upon the minute lichens, fungi, 
sooty molds and algae that grow on the bark and 
leaves of trees, shrubs, etc. They use their radulae 
to scrape these foods and loose particles of bark 
from the hammock vegetation. Newly hatched 
snails begin feeding at the bases of trees and, 
during periods of wet weather, work their way to 
the tops of the trees, feeding as they go. 

In the descriptions of the forms that follow, I 
have used the words large, medium size and sub- 
solid in describing the size and solidity of shells. 
One should understand that the size and solidity 
of Liguus shells are determined to a lesser degree 
by heredity and to a greater degree by the 
amount and quality of the snail food found in a 
hammock. It follows, therefore, that when one 
describes the size and thickness of a Liguiis shell, 
one describes to a greater degree the condition of 
the hammock as it relates to Ligims and to a 
lesser degree the inherant nature of the shell 
itself. For example: if one took, say, 45 newly 
hatched graphicus from one small colony, divided 
them equally into three lots and put one lot in a 
hammock with a maximum amount of food on 
the lysiloma and Jamaica dogwood trees; the sec- 
ond group in an identical hammock with a mini- 
mum of food; the third lot in a hammock forested 
principally with bustic and hackberry with opti- 
mum food, one would get three very different 
results. If one were to describe the size and 
solidity of each group at the end of the third 
year of activity, the descriptions would be ap- 
proximately as follows: 

First group - largesize(up to70mm.), solid; 

Second group - small size (up to 46 mm.), thin; 

Third group - large size (up to 65 mm.), thin. 



These facts were not understood by some describ- 
ers of Liguus and it has caused confusion and dif- 
ficulty in subsequent identifications of some 
forms of snails. 

Liguus fasciatus humesi, new form 

Figs. .5, 6 
Description: Shell medium size (up to 55 mm. 
in length), moderately elongate, subsolid; texture 
lustrous in young shells to dull in old specimens; 
whorls not inflated, slightly convex; columella 
sinuate to straight, thin; palatal lip smooth, occa- 
sionally crenate at juncture of periostracal green 
lines, slightly thickened within. 

Color, apex pink; columella and parietal wall 
invariably white except in thin shells where the 
color of the shell penetrates the very thin white 
callus which produces a slight pinkish effect; 
there is a narrow white to creamy brown sutural 
line; the third whorl is light-pink to brown and is 
marked with a few brovm axial striae; the color 
of the fourth, fifth, sixth and last whorls is dark- 
brown to almost black, broken by irregular 
yellowish axial stripes (which are often zigzag) 
and blotches that often extend from suture to 
suture on the fourth, fifth and sixth whorls and 
from suture to the base of the shell on the last 
whorl; there is a narrow yellowish peripheral 
band that produces a dark band, broken by 
yellow axial flames and/or blotches, above and 
below the periphery. A small percentage of shells 
have a few spiral green lines above and/or below 
the periphery. 

Type material: The form humeri is found only 
in an isolated group of hammocks of the southern 
Everglades. The holotype and paratypes were col- 
lected March, 1962. The holotype has been placed 
in the United States National Museum, Washing- 
ton, D.C. It is a four-year-old shell; length 46 
mm., width 23 mm., aperture width 23 mm., dis- 
tance from suture to base of shell 21.5 mm. 
Paratypes have been placed in the United States 
National Museum, Washington, D.C, the 
Museum of Comparative Zoology, Harvard Uni- 
vereity, the Academy of Natural Sciences of 
Philadelphia, University of Florida, Gainesville, 
and the Everglades National Park Collection. 
Homestead, Florida. 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 155 



A lot of 129 shells, collected without selection 
included the following forms: 

castaneozonatus U>1 78% 

cingidatus 11 9"/° 

humesi 9 7% 

fi-amptoni 5 4% 

'luteiis 3 2% 



129 



100% 



The color form humeri differs from the form 
castaneus by always having a white columella 
and parietal wall and by the absence of the single 
or double peripheral bands. 

In 1964 a group of humesi was introduced into 
a hammock containing no Liguus. Since then I 
have visited this hammock scores of times during 
the last 15 years and have not seen any of the 
other forms associated with it in its native 
habitat. 

It is with great pleasure that I name this shell 
for one who has played a significant part in the 
history of Ligiuis in Florida, Mr. Ralph Humes, 
now of Leesburg, Florida, intimate friend, de- 
lightful snailing companion and dedicated conser- 
vationist. He donated his fine large Liguus collec- 
tion to the Everglades National Park. He is the 
originator of the Park Liguus project on which he 
collaborated until he moved from Miami. Mr. 
Humes described the color form wintei and wrote 
a history oi Liguus collecting in Florida. 

Liguus fasciatus framptoni, new form 
Figs. 7, 8 

Dfscriptinn: Shell medium size, (up to .55 mm. 
in length), moderately elongate, subsolid; texture 
lustrous in young to dull in old shells; whorls not 
inflated, slightly convex above the periphery; col- 
umella sinuate to straight, thin; palatal lip 
smooth, occasionally crenate at juncture of 
periostracal green lines, slightly thickened 
wathin. 

Color: apex pink with a minute brown spot on 
its summit: columella and parietal wall in- 
variably pink or liver-colored; there is a narrow 
creamy brown sutural line; the third whorl is 
creamy brown, sometimes with faint narrow light 
brown axial streaks; the color of the fourth, fifth, 
sixth and seventh whorls is dark-brovm, broken 
by irregular yellowish axial striae (which are 
often zigzag) and blotches that often extend from 
suture to suture on the fourth, fifth and sixth 



whorls and from the suture to the base of the 
shell on the last whorl; there is a narrow 
yellowish peripheral band that produces a dark 
band, (sometimes wanting on the last whorl) 
broken by yellow axial flames and/or blotches, 
above and below the periphery. A small percent- 
age of shells have a few faint spiral green lines 
above and/or below the periphery. A brovra or 
purplish sinuating line borders the parietal wall 
from termination of the suture to the tip of the 
columella. It is a parallel form to humesi, differ- 
ing only in the light -brown coloration, the pink 
or liver -colored columella and parietal wall and 
the pink apex with the minute brown spot at the 
summit. 

Type material: This color form is found wath 
humesi, castaneozonatus, cingulatus and luteus in 
an isolated group of hammocks of the southern 
Everglades referred to above in the description of 
humesi. The holotype, a three-year-old shell, has 
been placed in the United States National Mu- 
seum, Washington, D.C. Its length is 47 mm., 
width 23 mm., aperture width 12 mm., distance 
from suture to base of shell 21 mm. Paratypes 
have been placed in the United States National 
Museum, Washington, D.C, the Museum of Com- 
parative Zoology, Harvard University, the 
Academy of Natural Sciences of Philadelphia, 
University of Florida, Gainesville, and the 
Everglades National Park Collection, Homestead, 
Florida. 

The offspring of a number of framptoni in- 
troduced several years ago into a hammock 
devoid of Liguus were predominately framptoni, 
some humesi, luteus and very rarely castaneo- 
zonatus. 

I have named this form in honor of Henry G. 
Frampton (1902 - 1966), one of the early modern 
collectors of Florida Liguus, who contributed to 
the literature by describing the forms splendidus, 
fuscoflammellus and clenchi. His widow, 
Theodosia, presented his fine, large Liguus collec- 
tion to the Museum of Comparative Zoology, Har- 
vard University. 

Liguus fasciatus evergladesensis, new form 

Figs. 1, 2 
De.'icription: Shell medium size, moderately in- 
flated, subsolid, texture matt or without much 
gloss; whorls convex, last whorl well rounded; 



156 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 




FIGS. 1-12. Ncir aiUir forma i//' Liguus fascial as (MHJIri) fraiii tin Hunihi Erny(nd(x. Aiicrho-nl ririrs (ire hulnlftixs. dfD-xal 
itiews are paralj/pes. 1, 2, evergladesensis. 3, 4, margaretae. .'5, 6, luimesi. 7. 8. fiamptoni. 9, 10. keiiiiethi. 11. 12, beardi. .4// 
formae nnvae./(;HP.s. 1.979. 



Vol.i»4 (1) 



October 30. 1979 



THE NAUTILUS 157 



sutures not ver>' deep, well shouldered; columella 
usually thin, straight and simple, occasionally 
slightly sinuated; palatal lip smooth, slightly 
crenate at juncture of periostracal green lines, 
slightly thickened within. 

Gill))-: apex, columella and parietal wall in- 
variably pink. Ground color is light-yellow. Tlie 
antepenult whorl is marked by a broad smoky 
lavender band broken by yellow vertical flames 
or blotches. Above and below this band are nar- 
row i-ufescent bands. On the penultimate and 
body whorls the broad band degenerates into 
alternating vertical smoky lavender and light- 
yellow flames. The two narrow bands become a 
series of comma-like blotches. The yellow ground 
color predominates. On the body whorl, the ver- 
tical flames are broken at the periphery' by a 
very light-yellow band and/or a lavender line. 
The columella is bordered by a narrow pink line. 
There is a narrow reddish brown basal line which 
is often reduced to a series of blotches. Almost all 
shells have from one to five spiral green lines 
ab(3ve the periphery and from one to four below. 

Tifpe material: The type locality is one of a 
group of four or five hammocks about one mile 
west of Canal Levee 28 about six miles north of 
the 40-Mile Bend of the Tamiami Trail. The 
holotype has been placed in the United States 
National Museum, Washington, D.C. It is a 
three-year-old shell: length 48 mm., width 25 
mm., aperture width 14 mm., distance from 
suture to base of shell 23 mm. Paratypes have 
been placed in the United States National 
Museum. Museum of Comparative Zoology, Har- 
vard University, the Academy of Natural 
Sciences of Philadelphia, University of Florida at 
Gainesville and the Everglades National Park 
Collection, Homestead, Florida. 

Comments: Form erergladesensis. in its first 
year superficially resembles castanetis but in 
later growth the juxtasutural bands are absent or 
reduced to a series of blotches. The columella and 
parietal wall are invariably pink whereas in most 
castaneiis they are white. It is unique among 
Pinecrest and Collier County subspecies 
testudineus, being the only form having a full 
pink tip. I doubt if there is any close genetic rela- 
tionship between evergladesenfsis and castanem. 
Over 50 miles separate the two forms. The closest 
hammocks containing castaneus are those of the 



L)ng Pine Key area near Homestead. The form 
evergladesensis is found with livingntoni, the 
predominant form, and with the form floridanus. 
It is interesting that while they are found in a 
pol^Tnorphic population they breed true to form 
when isolated. Such populations introduced in 
two s(juthern Everglades hammocks in 1961 have 
never produced any other forms. 

Liguus fasciatus margaretae, new form 
Figs. .3, 4 

Description: Shell large (to 64 mm. in length), 
elongate; texture subsolid with a sheen but ap- 
pears dull; body whorl convex, well-shouldered; 
penultimate whorl convex; the antepenult, fourth 
and third whorls flat; columella straight, not 
thin, slightly twisted, occasionally obliquely trun- 
cated; palatal lip slightly thickened within, 
usually crenate at juncture of periostracal green 
lines which are numerous and always present. 

C(ilo)" columella and first two or three whorls 
of spire are white. There is a narrow supra- 
sutural creamy yellow band and a subsutural 
mahogany-colored line. The fourth whorl is 
ivoiy-white broken by reddish brown subsutural 
spots that often develop into vertical striae that 
extend downward almost to the suture. The fifth, 
or antepenult whorl, has a broad bluish gray 
band broken by light-tan vertical flares that in- 
creasingly diffuse on the penultimate and body 
whorls and on the body whorl are overlaid with a 
blue-green wash above the reddish mahogany 
peripheral line and a wide darker green wash 
below the light-tan narrow band that lies im- 
mediately below the peripheral line. There is 
often a baby-blue line immediately above the 
))eripheral line. An orange basal band borders the 
columella and it is bordered by a much darker 
band that extends from the base of the shell to 
approximately two-thirds the distance to the 
suture. 

Type material: Tlie type locality is a small 
hammock of the southern Everglades. The holo- 
type is a mature, three-year-old shell, length 
.54.5 mm., width 26 mm., aperture width 13 mm., 
distance from suture to base of shell 22.5 mm. It 
has been place in the United States National 
Museum. Washington. D.C. Paratypes were also 
placed there and in the collections of the 
Everglades National Park, Homestead. Florida. 



158 THE NAUTILUS 



October 30. 1979 



Vol. 94 (4) 



Museum of Comparative Zoology, Harvard Uni- 
versity, Academy of Natural Sciences of Phila- 
delphia and the University of Florida at Gaines- 
ville. 

Comments: TTiis race of snails descended from 
five snails that appeared in a hammock in which 
I had placed together lucidovarim from Pinecrest 
Hammock No. 11 and clenchi from Pinecrest 
Hammock No. 88. One of these shells had a so- 
called "jewel tip", or apex of pinkish brown. This 
population produced the two above-mentioned 
forms, lossmanicus, many intermediates and the 
five ancestors of margaretae. 

The five snails were transferred to another 
hammock which had no snails. Two years later I 
returned and saw about 15 newly hatched snails 
(all of the white-tipped form), three white-tipped 
parents and the dead jewel-tipped shell. If this 
jewel-tipped snail died before it mated it could 
account for the white-tipped offspring. 

One would expect to find the polymorphism of 
the first hammock to show itself in the snail 
population of the second hammock but this has 
not occurred. Since the introduction in July, 1969 
all offspring have been margaretae. 

The distinguishing characteristics of 
margaretae are the light blue-green wash over 
the body whorl and the spire pattern of lucida- 
varl'm. In recently collected shells the wash ap- 
pears to be more blue than green but as the colors 
fade green predominates. 

I name this shell for my wife whose patience 
and understanding made it possible for me to 
spend many thousands of hours in the field these 
45 years since I first began snailing in 1934. 

Liguus fasciatus beardi, new form 
Figs. 11, 12 
Description: Shell similar to that of 
margaretae, except for color and pattern. First 
whorl of spire pink, faintly tinged with brovwi at 
the summit. Next two or three whorls ivory-white 
or white, sometimes flecked with ochre. There are 
supra and subsutural light-brown lines which are 
darker, heavier and broken on the antepenult 
whorl. On the penultimate whorl this line some- 
times appears as brownish spots. The overall m/- 
or of the shell is grayish brown wash, broken at 
the periphery by a wide, lighter colored band 
which is dissected by a heavy, browTi or maho- 



gany line. There are usually four or five green 
lines above and about three or four brownish 
green ones below the peripher\'. The columella is 
white or nearly so. The parietal wall is light- 
purple. There is a brownish purple line bordering 
the parietal wall which extends from the suture 
to the tip of the columella. Bordering this line at 
the base of the shell is a lighter colored band 
sometimes bordered by a darker one. 

Tifpe material: The type locality is a small 
hammock of the southern Everglades near the 
t.\i)e locality of margaretae. The holot\T3e is an 
adult three-year-old shell: length 54 mm., width 
26 mm., aperture width 14 mm., distance from 
suture to base of shell 24 mm. The holotype has 
been placed in the United States National 
Museum, Washington, D.C. Paratypes have been 
placed in the United States National Museum, 
the Everglades National Park Collection, 
Homestead, Florida, Museum of Comparative 
Zoology, Harvard University, Academy of 
Natural Sciences of Philadelphia and the Univer- 
sity of Florida, Gainesville. 

Comments: There is almost a total lack of ver- 
tical markings of any sort, except as described 
above. Occasionally a shell will have a trace of 
the blue-green wash of margaretae on the body 
whorl. 

It gives me much pleasure to name this shell 
for Dan Beard, first superintendent of the 
Everglades National Park, whose foresight and 
encouragement made possible the introduction of 
rare and beautiful forms of Lignus into the Park 
where, hopefully, they will be saved for future 
generations of scientists to study and for Park 
visitors to observe and enjoy. 

Liguus fasciatus kennethi, newform 

Fi^s. 9.1(1 

Description: Shell large (to 62 mm.), moderate- 
ly elongate, subsolid to solid, somewhat lustrous 
to dull; whorls 7-7':, convex; columella heavy, 
straight but slightly twisted, obliquely truncated. 

Color: first three whorls of the apex and col- 
umella ivory-white, parietal wall veiy light-flesh 
color. The ground color of the body whorl is 
yellow with an overlay of blotches, smears and 
v(>rtical strijies of burnt umber and umber which 
fade with time to yellow-ochre. There is a very 
narrow yellowish cream subsutural line and a 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 159 



narrow (1 - 2 mm.) peripheral band of the same 
color, sometimes bordered above by a lavender 
line. As the colors fade, each year's markings 
become lighter so that in some old shells the 
whorls above the body whorl are almost white. A 
few specimens show on the body whorls some 
spiral bandings as in the form floridanus. 
Periostracal green lines seldom present and few 
in number. Grovrth-rest varices slightly expanded. 

Type material: The type locality is a small 
hammock of the southern Everglades. The holo- 
type is a four-year-old shell, length 59 mm., width 
28 mm., aperture width 15.5 mm., distance from 
suture to base of shell 26 mm. The holotype 
has been placed in the collection of the United 
States National Museum, Washington, D.C. 
Paratypes have been placed in the United States 
National Museum, the Museum of Comparative 
Zoology, Harvard University, the Academy of 
Natural Sciences of Philadelphia, University of 
Florida, Gainesville, and the Everglades National 
Park Collection, Homestead, Florida. 

Comments: The progenitors of kennethi first 
appeared in Pinecrest Hammock No. 13 into 
which Mr. Erwin C. Winte had comingled some 
introduced Liguus with the native population. 
Unfortunately, no records were kept and in- 



formation as to the identity of the forms in- 
troduced is uncertain. Mr. Winte and I isolated 
five snails of this new form in a barren ham- 
mock. Later most of the progeny were transferred 
to another hammock. Since then, the two colonies 
have remained monomorphic. This phenomenon, 
plus the fact that kennethi shows no similarity to 
any of the forms of the original population leaves 
its geneology uncertain. Its overall shape and ap- 
pearance indicate only mainland forms were in- 
volved but its somewhat glossy appearance in five 
and six-year-old specimens suggests the influence 
of a Florida Keys ancestor. 

I name this snail for my son whose help in the 
exploration for suitable hammocks, collecting 
Ligims material and establishing it in the 
Everglades National Park contributed substan- 
tially to the success of the Park Liguus Project. 

LITERATURE CITED 

FVampton. Henry G. 19.32. Pr<ic. Biological Society of 

Washtngton, DC. 45:55-57. 
Humes. Ralph H. 19.54. Go-sCropirfm 1(2):10. 

1965. Tequesta, No. 25:67-82. 

Pilsbry, Henry A. 1946, Academy of Natural Sciences 



Philadelphia. Monographs No. 3. 2(part 1):37-102. 
Simpson, Charles T. 1929. Proc. United States 
Museum 73(Art. 20):l-44,pls.l-4 



of 



National 



CHICOREUS COSMANI, A NEW MURICID GASTROPOD FROM THE 

WEST INDIES 



R. Tucker Abbott 

American Malacologists, Inc. 
Melbourne, Rorida 32901 



C. John Finlay 

and 116 Tanglewood Lane 

Newark, Delaware 19711 



Despite the fact that the taxonomy of the fami- 
ly Muricidae has recently suffered under the 
hands of various conflicting interpretations (E. H. 
Vokes, 1971, Radwin and D'Attilio, 1976; Wagner 
and Abbott, 1978), new, apparently valid, taxa 
continue to come to light (Emerson and D'Attilio, 
1979). Contributing to our knowledge of marine 
mollusks is a corps of enthusiastic SCUBA divers 
and ardent private shell collectors. An outstan- 
ding example are the collecting efforts of Mr. 
Dieter Cosman of Long Island, New York, who 
has personally collected and documented numer- 



ous outstanding conchological discoveries in the 
tropical Western Hemisphere. 

Among Mr. Cosman 's unusual discoveries is a 
colony of Chicoreus muricid snails from Jamaica 
representing a species which evidently has not 
been given a valid, scientific name. We take great 
pleasure in naming this new species after him. 

Chicoreus cosmani new species 

(Figs. 1-9) 
Description: Shell moderate in size for the 
genus, attaining a length of 79 mm., trigonally 



160 THE NAUTILUS 



October 30. 1979 



Vol. 9-1 (1) 




F^KiS. 1-9. Chiaireus cosmani Ahhntt and Finlay. new xpcriem. Orhn Rios. Jiimmcn. 5, in the center is the halatjipe. 7!) mtn. in 
Icmjth. the other Jiyurex are ixirntifftesfnim the name locality. Collected by Dieter Coxman. Maivh 1967. 



Vol. 91 (1) 



October 30. 1979 



THE NAUTILUS UH 



fusiform in shape. Spire acute, with an angle of 
35° to 40°, and about 45 percent of the entire 
length of the shell. Nuclear whorls 1 1/2 glossy- 
smooth, convex, small but bulbous, whitish to tan, 
and with a well-indented suture, followed by S or 
9 convex, well-sculptured, p(_)st -nuclear whorls. 
First few whorls with a cancellate sculpture be- 
tween the varices. Suture finely impressed and 
slightly wavy. Aperture relatively small, about 
one-fourth the length of the entire shell, and with 
the peristome entire. Parietal wall glossy, slightly 
raised, and tinted with yellow, orange-brown or 
pinkish. Outer lip scalloped and bearing 10 to 12 
minute, raised, white denticles. Siphonal canal 
moderately broad, nearly sealed, and slightly 
recurved dorsally and to the right at the distal 
end. Former siphonal canal half as large, tube- 
like, recurved to the left, and bearing on its sur- 
face a half-dozen axial, irregular, small cords. 
Last (and earlier) whorls with three varices, 
originating just behind the varix above it on the 
previous whoi'l. Each varix in the body whorl 
bears 8 short, bi- or tri-furcate, scaly, partially 
(or rarely entirely) closed fronds. Tliree of these 
fronds are on the right side of the siphonal canal. 
In the early whorls the top frond is usally twice 
the size of those below. Intervarical sculptui'e 
consists of 4, I'arely 3, even-sized axial, low cords 
whicli ai'e crossed by numerous finer, spiral 
cords, thus foi-ming a pattern of low, rounded 
beads, oi- tiny knobs, all about the same size. Col- 
or of shell varies from a uniform brownish 
orange to a pale yellow orange, rarely white. In- 
terior of aperture white, with an orange-stained 
columella. Operculum chitinous, light-brown, oval, 
unguiculate. with fine, scaly concent ic giviwth 
lines. 



Measurements (mm) 



length 

79 
67 
38 
29 
2.5 



tmdth 
(tvith ifpines) 
40 
.3.3 
21 
17 
1.5 



10-F 
9-1- 
7.5 
8.0 
7.0 



no. whorls 

holot)^*. fig. 5. 
parat>'pe,fig. 7. 
parat.vpe, fig. 6. 
paratype, fig. 3. 
parat>T)e.fig. 2. 



Type Inaditij: on pilings at the Reynolds Baux- 
ite dock, Ocho Rios, north side of Jamaica. 10 to 
15 feet. March 1967. Dieter Cosman, collector. 

Tapes: Tlie holotyi)e (Fig. 5) has been de]>)sited 
in the U. S. National Mu.seum no. 78-332.3. Para- 




FIGS. 10, 11. Chicoreus species from Curaecu) resemUing 
cosmani. 29 mm. in length. Collected by Henk Bielderman, 
197-1 CiDistance Boone collection Photos courtesy of Emily 
Voke.'>. 

types are in the collection of Dieter Cosman, C. 
•John Finlay, the Academy of Natural Sciences of 
Philadelphia, the Amer. Mus. Nat. Hist., .Jerome 
Bijui', and the Delaware Museum of Natural 
History. Specimens have been reported as "very 
uncommon in about .35 feet at the Bogue Islands, 
Discovery Bay, Orange Bay and Bull Bay (ajuth 
coast), .Jamaica, in water as deep as 60 feet by 
Michael Humfrey (1975, p. 131, pi. 1.5, figs, 10, 
10a). We have not seen these specimens. One 
paratype (Acad. Nat. Sci. Philadelphia no. 3.5419) 
worn in condition, was collected by Robert Swift 
in St. Thomas, Virgin Islands, in the 1860's. 

Remarks: The Chicoreus complex in the Carib- 
bean is complicated by the existence of a number 
of species, subspecies and local, isolated forms, so 
that the present status of our knowledge is still 
far from complete. We believe that C. cosmani is 
a valid species, closely related to C. dilectus (A. 
Adams, 1855), brevifrons (Lamarck, 1822), spec- 
trum (Reeve, 1855) and flurifer (Reeve, 1845). It 
differs markedly from those other species in hav- 
ing 3 or 4 axial rows of rounded beads between 
the varices, somewhat reminiscent of the sculp- 
turing seen in Bursa pileare (Linnaeus). The 
other species usually have one large and one or 
two smaller knobs on the shoulder of the whorl. 
In breinfrons and mergus E. Vokes, 1974, the 
spire is much lower, the shell more quadrate, and 



162 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



the upper spine on the varix much larger and 
longer than those below. Closest to cosmani is the 
specimen from Curacao illustrated and identified 
by Ruth Fair (1976, pi. 6, figs. 73, 73a) as 
Chicoreus pudoricolor (Reeve, 1845). This may be 
a darkly striped, less beaded form of cosmani. 
The type and only known specimen of pudoricolor 
was returned to Denmark by Reeve, and has not 
been subsequently relocated. The original illustra- 
tion and description suggests a species more like 
corrwgatus (Sowerby, 1841) or a young spectrum. 
We consider pudoricolor a species inquirenda. 
The Indo-Pacific counterpart of cosmani is 
akritos Radwin and D'Attilio, 1976, from north- 
ern Australia. 

ACKNOWLEDGMENTS 
We would like to thank Dieter Cosman for his 

generosity in contributing the holotype to the 
U. S. National Museum, Smithsonian Institution, 



and Jerry Harasewych for his excellent photo- 
graphy, and Emily E. Yokes, Constance E. Boone 
and the Walter N. Carpenters for information 
and the loan of related species. 



LITERATURE CITED 

E>nerson, W. K. and A. D'Attilio, 1979. Six New Living 
Species of Muricacean Gastropods. The Nautilus 93(1):1-10. 

Fair, Ruth H. 1976. The Murex Book: An Illustrated 
Catalogue of Recent Muricidae. Honolulu, Hawaii. 138 pp., 
363 figs. 

Humfrey. Michael. 1975. Sea Shells of the West Indies. 
Taplinger Pub. Co.. NY. 3.51 pp.. 32 pis. 

Radwin, George E. and Anthony D'Attilio. 1976. Murex Shells 
of the World. An Rlustraied Guide to the Muricidae. Stan- 
ford Univ. Press. 284 pp., 32 pis. 

■Vokes, Emily H. 1971. Catalogue of the Genus Murex Linne; 
Muricinae, Ocenebrinae. Bu/i Amer. Paleont. 61(268):1-141. 

Wagner, R. J. L. and R. T. Abbott. 1978. Standard Catalog of 
Shells Supplement I pp. 13-801 - 13-810. American 
Malacologists, Melbourne, FL. 



POPULATION DYNAMICS AND ZONATION IN THE PERIWINKLE 
SNAIL, LITTORINA ANGULIFERA, OF THE TAMPA BAY, 

FLORIDA, REGION 



Susan B. Gallagher 

12250 6th Street East 
Treasure Island. FL 33706 



and 



St 



George K. Reid 

Eckerd College 
Petersburg, FL 33733 



ABSTRACT 
Seasonal changes in population density and size class distribution reflect the 
seasonal nature of reproduction in Littorina angulifera in the Tampa Bay. Florida, 
area The zonation pattern of adult snails and juveniles is described. Both extreme- 
ly high tides and a Gymnodinium breve "Red Tide" bloom reduced the population 
density. The Gymnodinium bloom killed new recruits differentially and had a 
long-lasting effect on the population density. The data show that most new 
recmits reach spawning size 9 to 10 months after metamorphosis. Most adults do 
not survive to spawn after two years, as there is an approximate 70 percent yearly 
mortality. 



INTRODUCTION 
This is our second report dealing with Lit- 
torina angulifera (Lamarck) in the Tampa Bay 



area. The first dealt with reproductive behavior 
and early development (Gallagher and Reid, 
1974); this report characterizes the composition 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 163 



and zonation of a Tampa Bay population of L. 
angulifera and describes seasonal changes in it 
from October 1971 through May 1975. In addition, 
two unusual natural environmental stresses oc- 
curred during the course of the study. Excessively 
high tides three to five feet above normal (Simon, 
1974), accompanied Hurricane Agnes in June 
1972 and an extensive outbreak of "red tide" 
caused by blooms of the dinoflagellate, Gipn- 
rmdinium breve, in the winter and spring 1974. 
Effects of these events are described and resul- 
tant changes compared with those in non-stress 
years. 

Although various Ldttorina species have been 
investigated extensively, only Borkowski (1974) 
has studied seasonal population changes and 
growth in groups of littorines over a period of 
several years. Palant and Fishelson (1968) 
reported on the reproductive cycles and ecology 
of L. punctata and L. neritoides in the Mediterra- 
nean Sea, but seasonal changes in population 
density and size distribution were not considered. 
Lenderking (1954), in her work on the biology of 
L. angulifera in the Miami, Florida, area studied 
growth, reproduction and size distribution pat- 
terns, but data were sparse on small snails 
because they were difficult to detect in the 
mangrove habitat in which she worked. Popula- 
tion density studies were not done. Hayes (1929) 



and Moore (1937) investigated shell growth in L. 
littorea; Moore also reported on spawning, length 
of life and mortality in this snail. Bingham (1972) 
investigated the growth and ecology of L. irrorata 
but none of these studies investigated seasonal 
changes in snail populations as reported here. 
Much has been done also on zonation patterns of 
littorines by Smith and Newell (1954), Evans 
(1965), Bock and Johnson (1967) and Chow (1975) 
among others. In addition to studies involving on- 
ly littorines, others have investigated desiccation, 
temperature and salinity changes, and behavior 
patterns in relation to observed zonation patterns 
of intertidal animals generally (Broekhuysen, 
1939; Kensler, 1967; Markel, 1971; and Vermeij, 
1972). There are very few investigations en- 
compassing the complete life history of pro- 
sobranch mollusks done in such a way that life 
cycles of the species can be illustrated from one 
spawning season to the next and so related to 
seasonal changes in population density and size 
distribution (however, see Frank, 1965). Results 
reported here, coupled with those obtained in a 
previous study on reproductive behavior (Gal- 
lagher and Reid, 1974) depict events in the life 
history of this snail, but we do not attempt to 
analyze the factors, whether physiological or en- 
vironmental which may be causal in these events. 



160- 

"o 

^ 140 



O 
ID 



20-- 



(VJ 



100- - 



\r-^ 



\ 



i ^•^■ 



\ t^ 



Hurricane Agnes 



.-^ Area A 
— -o Areo B 




Q z o 

no* 






1971 1972 1973 1974 I97S 

FIG. 1. Fluftuations }n population density o/Littorina angulifera /rom October 1971 through May 1975 in two areas of seaivall. 
Except for the large differences in recruitment in the fall of 1971 the populations densities in the two areas were similar. 



\M THK NAUTILUS 



October 30. 1979 



Vol. 91 (1) 



TAXONOMIC NOTE 
There is some question regarding the tax- 
onoinic status of this snail. Rosewater (1963) 
stated that it was a subspecies of the Indo-Pacific 
snail Littorina scahra and so should be called L. 
Hcuhra (DH/nlifpra. It was so called in our first 
report (Oallagher and Reid, 1974). However. 
Bandel (1974), in his study of Atlantic Lit- 
torinidae. more recently stated that radular dif- 
ferences between the two are such that they 
should be considered separate species. Because of 
this and because Abbott (1974) also considers 
these two as separate species, this animal is so 
considered in this report. Until this taxonomic 
problem is cleared up we believe it less confusing 
to refer to the organism as L. an(julifera since it 
is so designated in most of the literature. 

HABITAT 
Most of the animals in this study occupied a 
vertical concrete seawall bordering a canal in 
Boca Ciega Bay immediately south of John's Pass 
in Treasure Island, Florida (27°47'N, 82°47'W). 
The seawall habitat was chosen because of the 
ease of observing and counting animals on it in 



contrast to attempts to study these animals in a 
5pa/■^^«« -mangrove community. Although 
previous work (Gallagher and Reid, 1974) in- 
dicated that the seawall is a less favorable 
habitat than the Spart/na-mangrove area, obser- 
vations indicated that the same pattern of 
reci'uitment and zonation occurred in both places. 
Therefore, we felt results of this study would ap- 
ply generally to the species in this area. 

The seawall is composed of upright concrete slabs 
130-11(1 cm high and 120 cm wide; the canal bot- 
tom is composed of soft mud and oyster bar. Dur- 
ing the study the lowermost 30-40 cm of seawall 
were encrusted with oysters (Crassostrea 
riiyinicn) and barnacles (Biluitn.s lunphitrite. 
('hfh<tni(du.s spp.). Tlie isopod, Ligid sp. was one 
of the most conspicuous animals in the habitat. 
An intertidal zone approximately 9 m wide ex- 
tended horizontally from the base of the seawall 
since this much of the canal bottom was exposed 
at low spring tides. In 1971, at the beginning of 
the study, both L. anguUfem and L. irromta 
were present on the seawall, but during that year 
the numbers of the latter species gradually 
declined so that by 1972 none remained. 'Iliis 






65- 
60- 



(/i 



a 

(/) 55H 

w 50 

\ 45- 

._ '^0- 
D 
C 35-1 

(f) 

>. 3oH 

W 25- 

I ^°- 
CZ 15-1 

o 
o 

~B 5-1 

Q. 

O 
Q_ 



I \ 

I 
I 




/ 



I 
I 



■♦ "OLD" YEAR CLASSES 



O- 



■^^^3 NEW RECRUITS 



I I r 

Sept Oct Nov Dec Jon 
1971-72 




I r 

Sept Oct Nov Dec Aug Sept Oct Nov Dec July Aug Sept Oct Nov Dec 

1972 1973 1974 

FIG. 2. ConilMrisiin of imindnliiui density of new rn-nnts nml ulilcr i/ciir cldssiK of L. aiiKulifera in the iimntli^ m irhicli I Ik two 
Uroiips (ire ciixiliidi.itiiiiiiii.ihnL 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 1(55 



species continued to be abundant in local Spar- 
tina marshes but did not return to the seawall. 
Casual observation of other seawalls in the area 
showed that while L. nngnlifcra was frequently 
present, L. irrorata was rarely present, sug- 
gesting that it was less able to adapt to that en- 
vironment. Although these were the only two 
supratidal mollusks on seawalls several inteitidal 
mollusks inhabited the canal bottom. 

Several species of algae grew upon the en- 
crusted basal zone of the seawall. Tlie following 
species of Cyanophyta (blue green) were found: 
Anacystiii aeruginosa, A. montana. Por- 
phip-iisiphon noiarisii Schizotkrix arenaria. S. 
calcicola, Microcoleus lyngbyaceus, Entnphysalis 
de^ista, and Mastigncoleus testanim. The last two 
and Schlzothrir calcicola were found boring into 
oyster and barnacle shells in the upper parts of 
the encrusted zone. In addition to the blue green 
algae, several species of red and green algae were 
consistantly found on the lower 20 cm of seawall, 
usually where it was protected by an overhang of 
oyster growth and not subject to excessive desic- 
cation. The following species of Rhodophyta (red 
algae) were found: Polysiphonia suhtilissima, 
Centroceras clavulatmn, and Ceramium 
fastigiatum. Chlorophyta (green algae) included: 
iUva sp.. Entcromorplia roiiipin^m. E. liitgnlittn. 
Chaetomoi-iyha aerea. Qadophora delicatula, and 
Qadophora sp. In addition numerous diatom 
species were present. Both littorines fed in this 
zone but actual species eaten were not deter- 
mined. 



Thus, while creation of seawalled canals has 
apparently contributed to the decrease of species 
diversity in Boca Ciega Bay (Taylor and Saloman, 
1968; Sykes and Hall, 1970) some species are able 
to adapt to the conditions, especially if an inter- 
tidal zone is present. Since much of the shallow 
water area of this bay formerly consiting of 
grass flats, mangrove shores and Spartina marsh- 
es has been converted to seawalled canals (Simon, 
1974), we felt that studying snails in this type 
of environment might add to knowledge of some 
long-term effects of "dredge and fill" as well as 
provide information of the life cycle of L. anguli- 
fera. 



METHODS 

Pupulation fluctuations 

Population changes were studied by means of 
censuses of all L. angulifera in two areas of 
seawall. Area A was a portion of seawall 13.2 m 
long (eleven 120 cm slabs). Area B, 10.8 m long 
(nine 120 cm slabs) was located approximately 25 
m from Area A. All snails in these areas were 
counted every 2-3 weeks from October 1971 
through June 1972. and approximately each 
month thei'eafter through May 1975, with addi- 
tional censuses in May and July 1976. In some in- 
stances slightly longer intervals elapsed between 
counts. The seawall was 140 cm high in Area A 
and the substrate at the base was soft mud: the 
base of the wall was encrusted with oysters and 
barnacles. In Area B the seawall was 130 cm high 
and the substrate at the base was oyster bar; the 
base was also encrusted with oysters and bar- 
nacles, although the zone of encrustation was not 
as wide as in Area A due to the contour of the 
canal bottom. Total counts of L. angulifera were 
converted to population densities expressed as 
numbers of snails/m^ of seawall (Figure 1). From 
September through December of each year new 
recruits were recorded separately from previous 
year classes since size differences between the 
two groups were evident during censusing 
(Figure 2). 

Total shell height (from base of aperature to 
tip of spire) of random samples (including all 
snails on an area of exposed seawall at all levels) 
of usually at least 100 snails was measured to 0.1 
mm with vernier calipers to study the pattern of 
size distribution and growth. Sizes of samples 
taken after the 1974 red tide were small because 
of the decrease in snail population then, but such 
samples represent a large percentage of the re- 
maining population. The samples were taken near 
to but not in census areas and' usually were 
retui-ned to the seawall after measurement to 
avoid depleting the population and disturbing the 
census areas. Size distribution curves (Figure 3) 
are based on size classes of 1 mm intervals. 
Figure 4 depicts the seasonal variation in mean 
shell height for the population as a whole. 
Growth of new recruits during 1972-73 was com- 
pared with that of older snails (Figure 5) by 
calculating mean shell height of new recruits and 
older snails separately. During months when 



166 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



c 
o 



3 

Q. 

O 

CL 



o 

c 

if) 



19 Oct.. 1972 




Size Class 



FIG. 3. Seasonal variations in size class distribution o/L. angulifera /row October 1971 through May 1975. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 167 



c 
o 

B 

a. 
o 

Q_ 



o 

c 




Size Class 



FIG. 3. (continued) 



168 THE NAUTILUS 



October 30. 1979 



Vol. 91 (J) 



E 

e 



0) 



cn 

c 
o 




C3t-7'I>£^Sr>t/iOZOc_-n2>Sc-^>wOZOc_-ri2>5<_c_ 



1971 



1972 



1973 



1974 



i S S ^ 2 
1975 



FK'i. 1. .SV ii.<iiii(il riiniilitiiix In niciiii sliill In iijlit n/'L. anpulifera. 



sizes of the two groups overlapped a "cut-off' 
point based on relative numbers of individuals in 
different size classes was used. The same methods 
of cen.-^usinp and shell height measurement were 
continued during and after the high tide and red 
tide episf)des. Particular attention was paid to 
resultant changes. 

In addition to the 1974 red tide there was a 
less extensive outbreak in the summer of 1971. 
Accurate census data were not obtained at this 
time because snails in the census areas were 
disturbed during other studies, but data available 
indicate that there was a decline in population 
density as a result of exposure to two "patches" 
of red tide. 

Zonation Patterns 

Both the vertical migration and zonation level 
of adult snails were investigated during the 
spawning season from May to October. Addi- 
tionally the developing zonation pattern of new 
recruits was studied from November 1971 
through May 1972. The position of snails on the 
seawall was designated by dividing the seawall 
into six zones from biise to cap. The lowermost 
zone (zone 1) consisted of that part of the seawall 
encrusted with oysters and barnacles and varied 
from 30-40 cm deep depending upon the contour 
of the canal bottom. The next higher zone (zone 
2) included the area from the top of the encrusta- 
tion to a dark stain on the seawall and w;us 
uniformly 20 cm deep. The uppermost limit of 
this zone was that of Mean High Water Spring 
and the base of the seawall was at or just above 



Mean Low Water. The remaining portion of the 
seawall was arbitrarily divided into four addi- 
tional zones (zones 3-6) each 20 cm deep. All 
zonation study was done in Area A and snails 
therein were not moved or disturbed. 

To deteiTnine the zonation pattern of adult 
snails, numbei-s of individuals in each of the six 
zones in from 2-3 sections of seawall (about 
75-100 animals) were counted and that number 
converted to percent of all snails counted. Water 
level, time of day, and general weather conditions 
were recorded at each observation. If the tide was 
sufficiently low to uncover the entire seawall the 
water level was recorded as "0". Since snails were 
not ordinarily found below the base of the 
seawall, specific data on tides lower than this 
were not obtained. Observations included the 
hours from aiiproximately (1900 to 23iHi on 17 
different days during both neap and spring tides 
from 26 May to 2 October 1971, although not all 
days included the veiT late observations. Observa- 
tions were usually made four to five limes per 
day, but as few as three and as many as eight 
were made on .some days. 

Since newly recruited snails were not seen 
readily in the encrusted zone, the zonation pat- 
tern of these .small snails was studied only when 
zone I was under water and small snails visible 
on bare seawall. In this case the relationship be- 
tween the size of the snail and the di.stance above 
the waterline was determined and zones only 10 
cm wide were used. Figure 6 shows percentages 
of snails at different levels above the water and 
placement of snails as a function of size. Tlie two 



Vol. 94 (4) 



October 30. 1979 



THE NAUTILUS 169 



sets of data on zonation show different aspects of 
the life cycle. One illustrates the adult pattern of 
zonation and the other the development of that 
pattern. 

OBSERVATIONS AND RESULTS 

Population Changes 

a) General 

Data in Figures 1 through 5 show that there 
are seasonal changes in population density and 
mean shell height reflecting the seasonal nature 
of the L. angulifera reproductive cycle in this 
area. The first new recruits settled on the seawall 
sometime between late July and mid-August of 
each year studied. Increases in population density 
were evident by the end of August or early 
September; there then followed a period of from 
as few as 39 days to as many as 113 days when 
the population density increased. Greatest 
population density was reached during peak 
recruitment in the fall of each year studied. Ac- 
tual dates varied from late September in 1974 to 
mid-November in 1973, but after these dates the 
population declined steadily and reached a yearly 
low in July or August just before recruitment 
began again. 

The smallest snails settling on the seawall 
were 1..5 mm total shell height but most newly 
settled individuals were in the 2.0-2.9 mm size 



class and had five or six whorls. Attempts to find 
presettlement snails in the environment failed, so 
that the course of development from swimming 
veliger with a maximum shell length of only 0.13 
mm (Gallagher and Reid. 1974) to those capable 
of settlement at 1.5 mm as found here is 
unknovm. Length of time spent in the pelagic 
stage can be estimated, however. In 1971, peak 
spawning occurred during late August and early 
September (Gallagher and Reid, 1974) and peak 
recruitment occurred in early November (Figures 
1 and 2). Thus about eight to ten weeks elapsed 
between maximum spavraing and maximum 
recruitment; this likely represents the length of 
pelagic life for this snail. 

Comparison of Figures 1 and 4 shows that 
mean shell height of the population varies in- 
versely with density. This is due in part, of 
course, to the presence of large numbers of new 
recruits during certain months, but in years of 
greatest overall density snails tended to remain 
smaller than in years of overall low density. A 
weak positive correlation (r = 0.74) between densi- 
ty and mean shell height of adult snails com- 
pared and tested by the X^ method was found. 

Size distribution curves (Figure 3) show 
seasonal changes in recruitment and growth. 
There is a distinct bimodal pattern in late sum- 
mer and fall, although numbei-s of adults 



20- 

El6- 
.E 14- 
^ 12- 

a> 

a> 10- 

X 

-C 6- 

(r> 

c 4- 
o 

<U 2- 




-cr-- 



.o" 



<^o' 



O— ^^O FIRST YEAR CLASS (NEW RECRUITS) 
^— ^^« OTHER YEAR CLASSES 



O' 



Sept Oct Nov Dec Jon Feb Mor Apr May June July Aug Sept Oct 

1972 1973 

FIG. .5. Gymparisnn of the mean shell heights nf new recruits and idder iiear elasses of {,. angulifera in 1972-7-1 to show dif- 
ferences in growth rate heticeen t he t wo i/roups. 



170 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



representing previous year classes were much 
smaller than those of new recruits. By the end of 
December the two distinct sizes could not be 
detected by gross observation but were still evi- 
dent in size distribution curves. By March, 
however, size distribution curves were no longer 
distinctly bimodal, indicating that growth of new 
recruits was greater than that of older year 
classes and that they were "catching up" to them 
in size. The total size range at this time was 
large, ranging from 3.0 to 20.0 mm shell height 
(except in 1974 following the red tide outbreak). 
In summer, during spawning and just before 
recruitment began, the size range was much 
smaller, being from 9.0 to 18.0 mm in 1972 and 
11.0 to 20.0 mm in 1973. Since snails can begin 
spawning at approximately 10.0 mm shell height 
(Gallagher and Reid, 1974). these data indicate 
that most surviving recruits reached spawning 
size toward the end of their fii-st year or at about 
9-10 months post metamorphosis. Thus the size of 
the total population in May, which is the start of 
the spawning seasfjn in the Tampa Bay area, can 
be regarded as the size of the breeding population 
at the start of any given breeding season. Figure 
5, which compares mean shell heights of new 
recruits and older year classes from September 
1972 through June 1973, shows the difference in 
growth rates of the two groups of snails. New 
recruits grew rapidly through the fall and winter 
while older year classes grew little or not at all 
during that period but increased in size from 
March to May. Apparently grovrth is minimal 
during spawning and winter months for adult 
snails but is lapid for new recruits until they 
reach adult size. 

b) Miwtality 

Although the data do not show seasonal 
changes in mortality rate which may occur in 
this snail, total yearly percent mortality can be 
detennined by converting the decrease in popula- 
tion density (from highest yearly density after 
fall recraitment to lowest yearly density just 
before recruitment) to percent of snails lost 
(Table 1). This gives approximate ten month 
"mortality rates" of 58 and 57 percent in 1971-72 
and 1972-73 respectively, increasing to 94.5 per- 
cent in 1973-74. the year of the extensive bloom 
of (hjnitiixliiiinin breve If 57-58 jiercent is con- 
sidered a normal ten month mortality (average 



5.75 percent per month) expected yearly mortal- 
ity can be extrapolated to be about 70 percent in 
an average year. Older year classes continue to 
decrease in density from September through 
December (Figure 2) while new recruits show a 
sharp increase in density for a period of six to 
twelve weeks during recruitment. Therefore there 
is a sharp decline followed by a more moderate 
rate of decrease (Figure 2). Apparently many 
new reci'uits do not survive even a few weeks in 
the intertidal environment, and older year classes 
decline in numbers throughout the year. 

The percent increase in snails also varied in 
different years (Table 2). Increase during recruit- 
ment in Area A was 235 percent following losses 
from the July 1971 red tide. Due to lack of sum- 
mer census data for Area B, the percent increase 
is not known. Figure 1 shows an exceptionally 
heavy recruitment for both areas, especially Area 
B. There is no explanation for this difference but 
population densities in the two areas were 
similar in all other years studied (Figure 1). Dur- 
ing the next two years there was a 90 percent in- 
crease in density (though actual numbers of snails 
were different) possibly representing a normal 
or average increase. Percent increase was excep- 
tionally large (462 percent) following severe 
population depletion after the 1974 red tide; 
actual population size, however, was greatly re- 
duced. The 1971 summer red tide, which con- 
sisted of only two "patches" in the study area, 
did not reduce the population to exceptionally 
low densities (Table 2). 

c) Effects of extremely high tides and a red 
tide bloom 

During the extremely high tides which ac- 
companied Hurricane Agnes in June 1972, water 
completely covered seawalls in the area, causing 

TABLE 1. Percent decrease in snail population (Area A) from 
highest yearly density at peak recndtment in fall of one year 
to lowest yearly density before recruitment starts in the 
folUnciny year. 

1971-72 1972-73 1973-74 



High Density* 


77.0 


.58.7 


47.5 


Low Density 


32.3 


25.0 


2.6 


Total Decrease 


44.7 


33.7 


44.9 


Pei'cent Decrease 


.58.1 


57.4 


94.5 



'Denisitv = number of individuals/m' seawall. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 171 



TABLE 2. Percent increase in snail poptdation during 
recruitment -Area A 



1971 



1972 



1973 



1974 



Low Efensity' 


23 


32.3 


25.0 


2.6 


High Density 


77 


61.6 


47.5 


147 


Total Increase 


54 


29.3 


22.5 


12.1 


Percent Increase 


2a5% 


90% 


90% 


462% 



'Density = number of snails/m" seawall. 

L. angulifera to crawl onto the cap of the 
seawall. This left many individuals stranded on a 
horizontal surface. Fifty stranded snails were 
marked with waterproof paint to determine if 
they would return to the vertical portion of the 
seawall. After five days five of them had 
returned, but subsequent observations showed no 
more did so. There was a sharp drop in popula- 
tion density from 59/m^ to 46/m^ in Area A 
(Figure 1) immediately after the storm. The 
decline was even greater in Area B which had ex- 
ceptionally large numbers of snails from the 
heavy fall 1971 recruitment. Resultant loss from 
these high tides was 27 percent in Area A and 42 
percent in Area B. As a consequence of greater 
loss in Area B, population densities for the two 
areas became similar and remained so during the 
remainder of the study. These population losses 
occurred suddenly over the course of a few days, 
and there was no subsequent increase indicating 
that stranded snails had returned to the seawall. 
Thus, such stranding constitutes a lethal hazard 
for this species in a seawall environment. It is 
possible that in a mangrove habitat snails would 
be able to move up and down greater distances 
on mangrove trees and probably not be stranded. 
In a Spartina marsh, snails would probably re- 
main submerged near the tops of Spartina stalks 
and if wave action or currents were strong be 
washed off and lost. Most snails remained sub- 
merged just under the cap of the seawall for 
several hours during the hurricane. Lowest densi- 
ty for that year was 32 snails/m^ (Figure 1) so ef- 
fects of Hurricane Agnes did not reduce sharply 
the actual numbers of spawning snails. No doubt 
the extremely large numbers of snails as a result 
of the heavy 1971 recruitment somewhat 
ameliorated the damaging effects of Hurricane 
Agnes on the population. 

An outbreak of red tide caused by the 
dinoflagellate Gymnodinium breve, occurred in 
the study area from February through March, 



1974. In the canal it appeared as patches of in- 
fested water and was not present continuously. It 
was most prevalent at high tides and tended to 
concentrate in the upper 30 cm of water. Often 
the accumulation was heaviest adjacent to the 
seawall as if the wind was pushing the dino- 
flagellates against the seawall which then acted 
as a barrier to its dispersal, hence some very high 
concentrations occurred here. The patch almost 
always dispersed on the outgoing tide or if the 
wind shifted. A new patch sometimes, but not 
always, occurred with the next incoming tide. 
Most patches extended between 5 and 10 m out 
from the wall and lasted approximately six 
hours. In the study area, most occurred from 
mid-February through March, but the outbreak 
in the Tampa Bay region lasted from January 
through April. Following the appearance of red 
tide in the canal, many L. angulifera were found 
dead and dying in the mud at the base of the 
seawall. Moribund animals seemed paralyzed and 
unable to withdraw into shells or attach to 
substrate. Many recovered when placed in non- 
infested seawater in laboratory aquaria but no 
controlled studies to determine effects of ex- 
posure time and concentration were done. 

There was a drastic reduction in the snail 
population as a result of the red tide. The popula- 
tion density on 24 January 1974 before any red 
tide appeared in the canal was 27 and 31 
snails/m^ in Areas A and B respectively. This is 
comparable to densities in those areas on 19 
January 1973 (36 and 32 snails/m^ Areas A and 
B). On 25 February 1974 a few days after the 
first appearance of red tide in the canal popula- 
tion densities were only 8 and 9 in the two areas 
(A and B). In 1973 density reduction after a com- 
parable time was only by three snails in Area A 
and none in Area B. There were further reduc- 
tions in the population until low densities of 2.6 
and 2.3 individuals/m' were reached in the sum- 
mer of 1974 (Figure 1), representing a 94.5 per- 
cent reduction from peak density in November to 
yearly low in August (Table 1). Density of the 
breeding population in May of that year was only 
3 snails/m^ in the two areas studied. Presumably 
similar changes occurred in other habitats in the 
area so that the breeding population of L. 
angulifera would be much reduced in the Tampa 
Bay region for the 1974 spawning season. 



172 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



Recruitment in 1974 began at the end of July and 
reached a peak in late September, slightly earlier 
than in previous years. The peak density reached 
in the fall of 1974 following the red tide of the 
previous winter-spring was 15 and 8 snails/m^ in 
Areas A and B, far below peak densities reached 
in other years (Figure 1) even though the percent 
of increase was much greater than in previous 
years (Figure 2). In May 1975 population den- 
sities were 12 and 9 indicating that the L. 
angulifera population was not back to pre-red 
tide levels and still had a very reduced breeding 
population. One year later in May 1976 popula- 
tion densities were 15 and 13 snails/m^ in Areas 
A and B, still below comparable dates for other 
years. The last census taken (July 1976) showed 
population densities of 12 and 5 snails/m^ in the 
two areas counted. Apparently the effects of red 
tide are long lasting for this snail for after two 
years the population had not recovered in terms 
of density. 

A marked increase in mean shell height from 
10.6 mm on 24 January to 13.8 mm (a total of 3.2 
mm) on 25 February 1974 accompanied the initial 
sharp decline in population density. On com- 
parable dates in previous years shell heights in- 
creased by 1.2 mm in 1973 and 0.4 mm in 1972. In 
addition, on 24 January (before red tide) sizes 
ranged from 4.0 mm to 20.0 mm (Figure 3). On 25 
February (after red tide) sizes ranged from 9.0 to 
18.0 mm. Since it is unlikely that snails in the 4.0 
to 4.9 mm size class could grow to 9.0 mm in that 
time, the data apparently indicate that mortality 
was greater among the small snails; indeed, none 
of the very small snails remained. Nearly all in- 
dividuals still alive were of adult size. It is 
probable, therefore, that the breeding population 
in May 1974 was made up largely of animals two 
or more years old. Thus, although few snails sur- 
vive through two spawning seasons, those that do 
would be important in species survival should an 
event which kills new recruits differentially oc- 
cur. 

Zonation Patterns 

a) Adult zonation and vertical movements 
Adult L. angidifera were never found sub- 
merged but always occurred above the water 
line. During low tide periods, snails might mi- 
grate down into the encrusted zone to feed, but 



as they became wet with the rising tide, they 
moved up and remained out of the water. In the 
laboratory, animals placed in aquaria with small 
amounts of water responded by crawling out of it 
within 5-10 minutes. Lenderking (19.54) noted 
similar behavior, and Hayes (1929), Evans (1965), 
and Bingham (1972) demonstrated similar 
responses in other species of Littorina. When 
kept in aquaria for periods of two or more weeks, 
however, L. angulifera migrated down to the 
water level on occasion and fed from algae 
covered rocks or shells. Records indicate no 
periodicity to these migrations but tidal tanks 
were not used. In this species, only spawTiing ap- 
peared to have true tidal and lunar periodicities 
(Lenderking, 1954; Gallagher and Reid, 1974). 

Data obtained from observations on vertical 
migrations of adult snails on the seawall show 
that most L. angulifera were found in zones 3 
and 4 or between 60 and 100 cm above the base of 
the seawall in Area A. Measurements of the 
water level at different tidal phases showed that 
extreme high spring tides generally reach no 
higher than 80 cm on the seawall, mean high 
spring tide was at the top of the dark stain on 
the seawall (zone 2), and mean low water just 
below the base of the seawall in the study area. 
Actual measurements on the seawall varied with 
the contour of the canal bottom, resulting in nar- 
rowing of the encrusted zone (zone 1), but the 
pattern of zojiation in terms of tidal level is the 
same, only the measurements are different. These 
observations show that L. augulifera is a supra- 
tidal snail occupying a zone corresponding to 
the level of high spring tides and almost always 
remaining out of the water. Since it is a species 
of quiet water areas and wave splash is not a 
factor, it is thus seldom subject to wetting 
from spray as are some supratidal animals. 

Movements into lower zones, presumably to 
feed, took place only when those zones were ex- 
posed but did not occur at every exposure. Data 
presented in Table 3 show that at any given low 
tide, whether neap or spring, usually less than 50 
percent of the adult snail population migrated in- 
to the encrasted zone, indicating such migrations 
for adults are relatively infrequent. Dates of 
heaviest migration occurred during more humid 
periods when rain had occurred or when low 
tides occurred in evening or early morning hours. 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 173 



Apparently snails were more likely to move when 
relative humidity was high. L. auyulifem did not 
crawl in the mud at the base of the seawall even 
during very low tides but always remained on 
the upright seawall; thus, they never moved 
lower than mean low water, and usually re- 
mained well above this level. The same pattern of 
zonation was also seen in Sixuiinn-nvdngnwe 
areas, where snails were found only on stems and 
prop stems of mangroves or Sixviina stalks, not 
crawling on sand or mud at bases of these plants. 

b) Zonation in new recruits 

Newly recruited L. anguUfera remained close 
to the waterline in a zone wetted by the minimal 
wave wash in the canal. This zone was very nar- 
row, usually not exceeding 10 cm. Snails nearly 
always moved up and down so as to remain in 
this wet zone, but they remained in the encrusted 
zone during ver\' low tides and did not move out 
over the mud at the base of the canal. 

Smaller snails are closest to the waterline and 
there is a progressive increase in size as distance 
fi-om the water increases until the snails reach 
adult size when they assume the adult position 
and are likely to be found distributed throughout 
the supratidal zone (Figure 6). There is nearly 
always a small percentage of adult snails near 
the waterline since snails go to the water (though 
they do not submerge), probably to prevent ex- 
cessive desiccation. During November, when 
mean size is small due to large numbers of new 
reciTiits, between 62.4 and 65 percent of all snails 
were within 10 cm of the waterline, and between 
17 and 25 percent were from 10-20 cm of it. By 
December and January, the percent of snails 
within 10 cm of the waterline had decreased to 
between 22 and 30.5 percent. Sizes of such snails 
remained small but there were fewer of them. 
Data presented in Figure 6 show changes in zona- 

TABLE 3. MUjratiiin into encmsted z<ine 2t)May tii 2 October 1972. 



tion pattern of new recruits as they grow to 
.spawiing size. With the exception of the unusual- 
ly low zonation pattern seen for 14 March, there 
is a general rise in zone level of this species as 
the size of snails increases; adult size is reached 
when animals are zoned at the level of high spr- 
ing tides. This occurs in May at the start of the 
spawiiing season when most new recruits have 
reached adult size. These observations also 
showed that during the fall and winter months, 
mature snails from previous year classes re- 
mained at the supratidal level; there was no 
seasonal shift in zonation pattern of adults as has 
been I'epoited for other intertidal snails (Frank. 
1965; Palant and Fishelson, 1968). Only the new 
recruits shifted from a waterline position where 
they remained wet to a dr>' position as they grew 
to adult size. Thus, the change in zonation pat- 
tern seen as postlarval snails reach spawning size 
can be considered a developmental phenomenon. 

DISCUSSION AND CONCLUSIONS 
The results presented here can best be sum- 
marized in Figure 7 which illustrates yearly 
changes in a population of L. anguUfera in the 
Tampa Bay, Florida, area. In this area all the life 
history stages are seasonal, therefore, it is easy 
to delimit them. Spawning occurs during the 
wanner months of the year (May to October). The 
pelagic larvae also develop and begin to settle 
during this time but peak recruitment is reached 
in the fall 8 to 10 weeks after peak spawning. 
Juveniles grow rapidly during cooler months of 
fall, winter and early spring; at the same time 
they attain the adult zonation pattern. Thus, dur- 
ing growth to adult size there is a change from a 
water-line position to a supratidal position. By 
late May most of the young snails are ready to 
spawn. Population changes and size distribution 



Percent Snails moving 
into Encrusted zone 



Number of Days Seen 


Percent of 


in Encrusted zone 


Total davs 


19 days 


4().ro 


.5 davs 


10.6% 


IBdavs 


40.-^ 


2 days 


4.3% 


2 days 


4.3% 



Less than ICf o 

10 ■ 25% 

2.5 -.50% 

.50-75% 
More than 75% 

Total number of days observed — 47 
The percent of snails seen in the encrusted zone during low tides on 47 different days of the 1972 spawning season. The days 
include both neap and spring tides. 



174 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



70 

60 
d 50 

<. 

2 40 




S 
5 
H 



I I" 

O 

I 

_,10 

_1 

X 

" 6 
Z 
< 4 

o 



70 

9 NOVEMBER, 1971 go 

50 
40 

30 
20 
10 

20 !C 40 50 60 TO eo 90 lOO 

IB 
16 
14 
12 
10 
8 





18 NOVEMBER. I97J 



27 NOVEMBER, 1971 



10 20 30 40 50 60 TO 80 90 iOO 



10 20 30 40 50 60 TO 80 90 100 




20 3C 4^1 50 fC 7C 80 90 lOO 




70 
60 



=! 50 

<I 



I- 
O 20 



Z 18 

Z 16 




14 



X 

o 

I 



CO 6 



DISTANCE ABOVE WATER LINE IN CM 

70 



12 DECEMBER. 1971 



10 20 3C 40 50 60 TO 80 90 100 




70 
60 
50 
40 
50 
20 
10 




4 JANUARY. 1972 



60- 
50- 

40- 

SO- 
SO- 
10 




>C 2C 30 40 50 60 70 80 90 lOO 




10 20 30 40 50 60 TO 80 90 lOO 



23 JANUARY, 1972 



iC 20 JC 40 5C 60 TO 80 90 lOO 




10 20 30 40 50 60 TO 80 90 lOO 



10 20 30 40 50 60 TO 80 90 100 



10 20 30 40 50 60 TO 80 90 100 



DISTANCE ABOVE WATER LINE IN CM. 



FIG. 6. Development of the zonation pattem in L. angulifera. The distance above the waterline as percent total snail population is 
related to median shell height. (Median shell height is used here rather than mean shell height in order to eliminate bias in- 
troduced by averaging the size of an adult snail which may be near the waterline— as mentioned such snails do occasionally 
migrate to the waterline but would belong to the adult group mther than the new recntits whose zonation pattern this figure 
depicts.) 



Vol.94 (4) 



October 30. 1979 



THE NAITTILUS 175 





70 








60 


12 FEBRUARY. 1972 


< 






z 


50 




CO 






-I 


40 




< 






H 


30 




o 






*- 


20 


^^ 


s« 


10 


imi «! 




lO 2C 10 40 50 e.C 70 80 90 lOO 


5 


18 ■ 




z 


IS 




t- 






I 


14 




o 












HI 


12 


^S jaBt/^E« 


X 






_] 


10 




-I 






^^^^H^ 


HJ 


e 




^^^^^^^ 


X 






^^^^^^^ 


to 


6 




^^^^s 


z 






^^^^^^^ 


< 


^ 




^^^^^^ 


o 






^^^^^^^ 


UJ 


2 




^^^^^^Bffi 


5 






^H^ 




14 MARCH. 1972 



70 
60- 
50 
40- 
30 
20 
10 



20 30 40 50 60 70 BO 90 lOO 





3-6 APRIL, 1972 



TO 80 90 lOU 




10 20 30 40 50 60 70 80 90 ;C0 lO 20 30 40 50 60 70 80 90 lOO 

DISTANCE ABOVE WATER LINE IN CM. 



70- 






« 60- 


20 APRIL. 197 


_l 




< 50' 




Z 




<n 




_i "" 




< 




1- 30 




O 




^ 20 




ss 


^M ■ 


10 


gl liy 




iO 20 10 4C 50 60 70 80 90 lOO 


S 18 ■ 




s 




2 16 ■ 






t- 14 ■ 






I 






^ ,2 






UJ 






I 10 






_l 






-1 8 






UJ 






X 






to 6 






2 






< 4 






Q , 






UJ 2 ^ 






S 




L 




'0 20 30 4C 5C %0 70 80 90 


00 



70- 
60 
50 
40 
30 
20 
10 



70- 
16 MAY. 1972 50 

50 
40 

30 
20- 




lO 20 30 40 5:J 60 ?0 80 90 lOO 



M JUNE. 1972 




(0 20 30 40 50 60 70 80 90 lOO 



lO 20 3C' 4C 50 60 70 80 90 lOO 



DISTANCE ABOVE WATER LINE IN CM. 



176 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



patterns reflect these chanpes. The yearly cycle in 
this area is much more sharply delineated than 
in the Miami area where, as shown by Lender- 
king (1954), spawning occurs throughout the year. 
It follows, as she showed, that other life stages 
are more or less continuous in that area also. No 
doubt the greater seasonal variation in 
temperature in the Tampa Bay area is, in part, 
responsible for differences seen between the two 
localities. 

Data and observations indicate that L. 
angidifera is a fast-maturing, probably short- 
lived species much like LItfnrina lineatcu L. 
linealatcu and L. ziczcw as reported by Borkowski 
(1974). Most snails begin spawning about 9 to 10 
months after metamorphosis. About 70 percent of 
them d(j not reach a second spawTiing season, 
much the same percent Borkowski (1974) found 
for species of the Littorina ziczae complex. 

Population changes in this snail are affected by 
a variety of factors. These include unusual en- 
vironmental events that do not occur regularly 
ever>' year. During the course of this study two 
such events, extremely high tides and a red tide 
bloom, occurred. Because population changes in 
groups of animals are susceptible to events of this 
nature which vary from year to year, it is dif- 
ficult to ascertain just what "average" or "nor- 
mal" changes are. This could only be done by 
observations over such a long period that effects 
of unusual events would cancel out. Obviously a 
three year study period is too short. In spite of 
this, however, changes occurring in the unusual 
years were compared with changes when no 
unusual events occurred. In this way some indica- 
tion of the magnitude of these environmental 
stresses was obtained. The results show that 
while these events caused drastic changes in- ac- 
tual population numbers, the general changes ac- 
companying the yearly life history remained the 
same. Of the two, the red tide bloom was more 
damaging than the extreme high tides. Not only 
were the immediate effects of the red tide bloom 
more severe but there were long term changes in 
p<jpulation density as well. Further, since the red 
tide differentially killed small snails, the com- 
position of the spawning pt^pulation the following 
year consisted primarily of older snails. Thus, the 
older group, small in numbers compared to the 
most recently spawTied group, had to make up the 



deficit caused by the high mortality among new 
recruits. As the data show, this caused a lasting 
effect on population density. 

Upon settling, very small snails remain close to 
the waterline and move upward as they grow and 
mature so that by the beginning of the spawning 
season in May the adult zonation pattern has 
developed. Other investigators have alsf) reported 
an upshore size gradient of this type for inter- 
tidal moUusks. Smith and Newell (1954) 
demonstrated that this occurred with L. littorea 
until the adult zonation pattern was reached at 
about one year of age, after which individual 
snails tended to remain at the level they had 
reached at that time. They did not report any 
vertical migrations of adults as noted here for L. 
aiHiulifcm. and by Bingham (1972) for L. irmrata. 
Palant and Fishelson (1968) found the same 
phenomenon for L. punctata in that small in- 
dividuals remained clustered in a wet zone near 
the waterline, while large individuals were found 
higher on the seawall. Chow (1975) reported an 
upshore size gradient in L. .'icutnlata. with 
smaller snails being found closer to the water. 
Frank (1965), in a study of population changes in 
the limpet Acmaea digitalL<!. found a similar size 
gradient, with largest and oldest animals being 
found higher in the intertidal zone. Vermeij 
(1972), in an excellent review, reported such a 
gradient for high intertidal to supratidal 
mollusks during post larval stages but the op- 
[josite gradient for those whose range was low to 
mid-intertidal. Chow (1975) found that while 
small snails were less resistant to desiccation 
than large ones, all sizes were resistant to desic- 
cation encountered in the envii-onment. Results of 
preliminary, as yet unpublished, experiments 
show that the same is true for L. augulifcra. The 
zonation pattern of juvenile snails results in 
favorable placement in respect to food and pro- 
bably helps to ensure frequent feeding excui-sions. 
TViis is likely necessary for snails to grow to 
maturity by the spawning season in May. It may 
\:>e more imiX)rtant in determining the zonation 
pattern of juveniles than resistance to desicca- 
tion. It is also possible, however, that placement 
lower intertidally was an important factor in the 
greater mortality of small snails during the red 
tide outbreak. Larger snails remained higher on 
the seawall and hence had a better chance to 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 177 




SPAWNING SEASON 



'Srowth of 1st Year Class to Spawning Size 






Develop men ui mOuII Zonation Patiern 



HIGHEST POPULATION 
DENSITY PER YEAR 






RECRUITMENT 



JLOWEST POPULATION 
DENSITY PE'r'yEAr|! 



i *::■ 



Growth of 1st Year Class to Spawning Size 



Development of Adult Zonation Pattern 



OCT NOV DEC. JAN. FEB MARCH APR MAY JUNE JULY 
FIG. 7. Diiifiniiii mitt ir ifjinsciiiatiiiii iiftlic i/fitrlti tiff 

escape it. Smaller snails also may be more 
susceptible to red tide toxins, but tests were not 
made. 

There is some evidence that snail growth may 
be density dependent since during years when the 
lowest density of the year is high, the greatest 
mean shell height for that year is lower than in 
years when the lowest density for the year is low 
(Figures 1, 4). VeiTneij (1972) reported this for 
the bivalve Tellina tenuis and Frank (1965) found 
that growth of Acmaea digitalis was reduced dur- 
ing crowding. Frank (1965) suggested that food 
availability may be a factor, and such may also 
be true here, although Bingham (1972) found that 
it was not important in the distribution of L. ir- 
rorata in a north Florida marsh since in that en- 
vironment an excess of food was available in all 
areas. The situation might be different on a flat 
seawall which would present less surface area for 
the growth of food organisms than would a marsh 
or mangrove habitat. Gallagher and Reid (1974) 
showed that L. angnlifera in a Spartina-ma.n- 
grove area had a larger mean size than those on 
a seawall, suggesting that food availability may 
be a factor in a seawall environment. 

Although this study illustrates and describes 
the yearly life history of L. angulifera in the 
Tampa Bay. Florida area much remains to be in- 
vestigated regarding factors regulating these 
events. Studies encompassing temperature 



AUG SEPT OCT NOV DEC. JAN FEB MARCH APR MAY 

histiiriiiifh. angulifera in the Tnnipii liii/. Ftundii. lu-rn. 

tolerance, desiccation resistance, and identifica- 
tion of food organisms are planned. 

ACKNOWLEDGMENTS 
We are deeply grateful to William G. Lyons, 
Supervisor of Invertebrate Studies, Florida State 
Department of Natural Resources, Marine Re- 
search Laboratory, St. Petersburg, Florida, for his 
critical reading of the manuscript. We also thank 
Ms Karen A. Steidinger, Laboratory Supervisor, 
for identification and measurement of the Gym- 
riiidinium breve blooms, and Dr. Harold J. 
Humm, Professor of Marine Science, University 
of South Florida, St. Petersburg, for confirmation 
of the algal identifications. We express great ap- 
preciation to Mrs. Sally D. Kaicher for prepara- 
tion of the figures and to Miss Stephanie 
Schminke for the typing. Financial support has 
been received from the Eckerd College Faculty 
Development Fund. 

LITERATURE CITED 

Abbott. R. T. 1974. Amenran Seashells. 2nd Ed. Van Nostrand 

Reinhold Co.. New York. 1974. 
Bandel, K. 1974. Studies on Littorina from the Atlantic. 

Veliger 17:92-115. 
Bingham. F. 0. 1972. The influence of environmental stimuli 

on the direction of movement of the supralittoral gastropod 

Littorina irmrata. Bull. Mar. Sn. 22:.309-a35. 
Bock. C. E. and R. E. .Johnson. 1967. The role of behavior in 

determining the intertidal zonation of Littorina planaxis 

Phillipi 1847 and Littorina scutulata Gould 1849. Veliger 

10:42.54. 



178 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



Borkowski, T. V. 1974. Growth, monality and productivity of 
South Florida Littorinidae (Gastropoda: Prosobranchia) 
Bull. Mar. Sci. 24:409437. 

Broekhuysen, G. J. 1939. A preliminary investigation of the 
importance of desiccation, temperature, and salinity as fac- 
tors controlling the vertical distribution of certain inter- 
tidal marine gastropods in False Bay, South Africa. Trans. 
Royal Soc. (if South Africa 28:255-292. 

Qiow, V. 1975. The importance of size in the intertidal dis- 
tribution of Littorina scutulata. Veliger 18:69-78 

Evans, F. 1965. The effect of light on zonation of the four 
periwinkles, Littorim littorea (L.), L. obtv.sata (L.) L. sax- 
alilis (Olivi) and Melarapha neritoides (L.) in an ex- 
perimental tidal tank. Neth. Jour. Sea Res. 2:556-565. 

Frank, P. 1965. The biodemography of an intertidal snail 
population. Ex;ology 46:831-844 

Gallagher, S B. and G. K. Reid, 1974. Reproductive behavior 
and early development in Littorina scabra angulifera and 
Littorina irrnrata (Gastropoda: Prosobranchia) in the Tam- 
pa Bay region of Florida. Malacohjgical Review 7:105-125 

Hayes, F. R. 1929. Contributions to the Study of Marine 
Gastropods. Ill Development, Growth and Behavior of Lit- 
torina. Contr. Can. Biol.. N.S. 4:413-430 

Kensler, C. B 1967. Desiccation resistance of intertidal crevice 
species as a factor in their zonation. Joum. Animal Ecol. 
36:391406 



Lenderking, R. E. 1954. Some recent observations on the 

biology of Littorina angulifera Lam. of Biscajtie and 

Virginia Kej-s, Florida. Bull. Mar Sci. Gulf & Carib. 

3:273-'296 
Merkel. R. D. 1971. Temperature relations in two species of 

West American Littorines. Ecolog>- 52:1126-1130 
Moore, H. B. 1937. The biology of Littorina littorea Part I. 

Growth of the shell and tissues, spawning, length of life and 

mortality. Jour Mar Biol. Assoc. UK 21:721-742 
Palant. B. and L. Rshelson. 1968. Littorina punctata (Gmelin) 

and Littorina neritoides (L) (Mollusca: Gastropoda) from 

Israel: Ecology and annual cycle of the genital s>'stem. 

Isreal Joum. Zool. 17:14.5-160 
Rosewater, J. 1963. Problems in species analogues in world 

Littorinidae. >lmer. MalacoL Union, Ann. Reps.. Bull 30:5-6 
Simon, J. L. 1974. Tampa Bay estuarine system - a s>Tiopsis. 

Flo. Sci. 37:217-244 
Smith, J. E. and G. E. Newell. 1954. The dynamics of the 

zonation of the common periwinkle Littorina littorea (L) on 

a stony heach.Jaum. Animal Ecol 23:35-56 
Sykes, .J. E. and J. R. Hall. 1970. Comparative distribution of 

moUusks in dredged and undredged portions of an estuar>-. 

with a systematic list of species. U.S. Fish and Wildlife 

Service Fishery Bulletin 68:299-306 
Taylor, J. H. and C. H. Saloman. 1968. Some effects of 

hydraulic dredging and coastal development in Boca Ciega 

Bay, Florida. U.S. Fish and Wildlife Sen^ Fish Bull. 

67:213-241 
Vermeij, G. J. 1972. Intraspecific shore-level size gradients in 

intertidal mollusks. Ecology 53:693-700 



SPHAERIIDAE AS INDICATORS OF TROPHIC LAKE STAGES 

Arthur H. Qarke 

Smithsonian Institution 
Washington, D.C. 20560 

ABSTRACT 
Analysis of field data associated mth 35 species of boreal and arctic North 
American Sphaeriidae indicates interesting correlations between species oc- 
currences and types of lentic habitats. A few species combine the attnbutes of 
stenotopy, broad geographical distribution, relative abundance and relative ease of 
taxonomic identification and appear to be of use as trophic lake stage indicators. 
These are: Pisidium conventus Qessin and Sphaerium nitidum Gessin for 
oligotrophic lakes, P. idahoense Roper and S. striatinum (Lamarck) for 
mesotrophic lakes, and P. rotundatum Prime and S. simile (Say) for eutrophic 
lakes. 



Tlie characterization of inland aquatic en- 
vironments based on mollusks frequently con- 
stitutes an integral part of Quaternary 
paleoecological studies (Camp, 1974; Gibson, 1967; 
Miller. 1966; Taylor, 1957; and Warner, 1968). In 
such studies the whole biological assemblage pre- 
sent (often consisting of pollen, ostracod shells, 
mollusk shells, and fish bones) or the mollusk 



assemblage alone (consisting of gastropod and 
sphaeriid shells and possibly also of freshwater 
mussel shells) may be analyzed and evaluated. 
The use of only a few critical species of 
Sphaeriidae for interpretation of paleoen- 
vironments, or for characterization of existing 
trophic lake stages, has not been attempted, at 
least in North America. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 179 



The Sphaeriidae (also known as Pisidiidae) 
(Superfamily Corbiculacea) are a large worldwide 
family of small freshwater, bivalved mollusks. 
Unlike the other native families of freshwater 
clams (Superfamily Unionacea) the shells are 
small (15 mm or less in most species), 
porcelaneous, and have lateral teeth both anterior 
and posterior to the cardinal teeth. The life 
histories of the North American species have 
been described by Heard (1965, 1977). 

A preliminary' summary of information con- 
cerning the relative abundance, regional geo- 
graphical distribution, and kinds of aquatic 
habitats occupied by the sphaeriids of northern 
North America is presented in Table 1. The 
species list is believed to be complete for Canada. 
With the exception of two warm -temperate 
species in the southeastern United States (Eupera 
cubensis (Prime) and Pisidium punctifeiitm (Gup- 
py)) and one. rare, relict species in northern 
California and southern Or^on (P. ultramon- 
tanum Prime), the list is also believed to be com- 
plete for the continental United States. Relative 
abundance estimates, distribution approxima- 
tions, and habitat identifications refer only to 
populations in Canada and northern United 
States. The abbreviations under Distribution 
refer to ph>togeographic regions (see brief sum- 
mary in Qarke, 1973). 

Inspection of the table reveals that most 
species are eur>topic, or wide-ranging in habitat 
preferences. Among those which are common and 
widely distributed, only a few are principally 
associated with lakes in any one particular stage 
of trophic development. These are, for 
oligotrophic lakes: Pisidium conventus and 
Sphaerium nitMum: for mesotrophic lakes: P. 
idahoense and S. striatinum: and for eutrophic 
lakes: P. rntimdatum and 5. simile. S. occidentale 
(uncommon in Canada but locally common in the 
United States) is characteristic of the most ad- 
vanced aquatic stage in lake development, i.e. 
swamps and temporary (vernal) ponds and pools. 



-wilful UTih 




t .«nlHul (oiih 


iw™. 




>-A 


\ 


\ ^ fWnixucTbunl 






\niT««.uiTU(Tjl 


11 


(~ 



FIG. 1. Parts of a sphaeriid shell (Pisidium idahoense Roper 
left and right valves from different specimens), semidiagram- 
maiic. 

The following short descriptions and the il- 
lustrations are designed to assist' limnologists 
who are unfamiliar with the Sphaeriidae but who 
wish to be able to identify the indicator species 
here selected. The structural terms used are 
defined in Figure 1 and the species are il- 
lustrated in Fig. 2 and 3. The beaks (umbones) 
are located dorsally and near the posterior end in 
most species of Pisidium. In species of sphaeriids 
which have the beaks more centrally located, the 
anterior and posterior of empty shells can be 
found by examination of the hinge teeth. The 
right valve bears a single, very small cardinal 
tooth located under the beak and 4 (2 pairs) of 
narrow, elongate lateral teeth, one pair located 
on either side of the cardinals. The left valve 
bears 2 cardinals and 2 single laterals which ar- 
ticulate with the corresponding teeth in the right 
valve. In life the animal moves forward with the 
beaks held upward, the right valve on the right 
and the left valve on the left. The most elevated 
part of each lateral tooth is the cusp. The posi- 
tion is proximal if it is close to the cardinal teeth 
(or tooth) and distal if it is far from them. 

The user is cautioned that positive identifica- 
tion of sphaeriid species is often difficult, 



TABLE 1 



(1) 



Relative Abunda 
Habitats of the Sph^ 



nee. Approximate Distributions, and Usual 
Sphaeriidae of northern North America^^^ 



Abbreviations. Abundance: C, abundant or common; R, uncommon or rare; I, recently 
introduced (relative abundance unstable). Distribution; A, arctic; T, arctic-boreal 
transition zone; B, boreal forest; M, western montane region; P, prairie and parkland 
region; G, Great Lakes-St. Lawrence forest region. Habitat: X, frequent occurrence; 
X, infrequent occurrence. 



180 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 





SPECIES 


a 

CO 

< 


DISTRIBUTION 


HABITAT 






W of 95° 


E of 95° 


OLIGOTR. 


MESOTR. 


EUTROPH . 


V-ERNAL 




Plsidlum waldeni Kuiper 


R 


A T 




X X X X 


J 






P. conventus Clessin 


C 


A T B M 


A T B C 


X X X X 


XXXX 








Sphaerlum nitidum Clessin 


C 


A T B M 


A T B C 


X X X X 


XXXX 


XXXX 






P. compressum Prime 


c 


T B M P 


T B C IX X X X 


XXXX 


XXXX 






P. lilljeborgi Clessin 


(■ 


A T B M P 


A T B R 


X X X X 


XXXX 


XXXX 






P. nitidum Jenyns 


{ 


A T R M P 


T B C 


X X X X 


XXXX 


XXXX 






P. subtruncatum Malm 


R 


A T B M P 


B C 


XXXX IX XXX 


XXXX 






P. casertanum (Poll) 


C 


T B M P 


T B C 


X X X X 


XXXX 


XXXX 


XXXX 




P. idahoense Roper 


c 


A T B M 


B r. 


XXXX 


XXXX 


XXXX 






P. fallax Sterki 


R 


B P 


B R 


XXXX 


XXXX 


XXXX 






S. striatinum (Lamarck) 


c 


T B M P 


T B G 




XXXX 


XXXX 






S. comeum (I.) 


1 




R 




XXXX 


XXXX 






P. amnicum (Mil Her) 


I 




G 




XXXX 


XXXX 






P. ferrugineum Prime 


c 


A T B M P 


A T B R 




XXXX 


XXXX 






P. henslowanum (Sheppard) 


I 




R 




XXXX 


XXXX 






P. supinum Schmidt 


R 




R 




XXXX 


XXXX 






P. variabile Prime 


c 


T B M 


T B G 




XXXX 


XXXX 






P. ventricosum Prime 


c 


T B M 


T B C 




XXXX 


XXXX 






P. walkerl Sterki 


R 


A T B M 


T B G 




XXXX 


XXXX 






S, transversum (Say) 


R 


BMP 


B G 




X X X X 


X X X X 




- 


P. adamsi Prime 


R 


B P 


B G 




XXXX 


XXXX 






P. mi 1 lum Held 


R 


IBM 


T B C 




XXXX 


XXXX 






S. lacustre (Muller) 


c 


T B M P 


T B R 




XXXX 


XXXX 






P. cruciatum Sterki 


R 




G 






XXXX 






P. dubium (Say) 


R 




C 






XXXX 






P. equilaterale Prime 


R 




B G 






XXXX 






P. punctatum Sterki 


R 


B M 


B G 






XXXX 






P. rotuindatum Prime 


C 


IBM 


T B G 






XXXX 






S. patella (Gould) 


R 


M 








XXXX 






S. rhomboideum (Say) 


R 


B M 


T B G 






XXXX 






S. simile (Say) 


C 




B G 






XXXX 






S. partumelum (Say) 


C 


B P 


B G 






XXXX 


XXXX 




S. securis Prime 


C 


BMP 


B G 






XXXX 


XXXX 




S. occldentale Prime 
P. Insigne Cabb 
S. fabale Prime 


R 


M 


T B R 
G 
G 


/ 1 




XXXX 

\ _ _ _ _ 


XXXX 




R 
R 


M 


- - - llOLic only/ -------- 

i ^ .^ f 1 ^ nnlitl ^ .• ^ ^ -M — ^ ^ 






— — — Miotic oniy^ _ - — - 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 181 



especially in Pisidium. Even though the eight in- 
dicator species are among the easiest to identify, 
for verification one should refer to Herrington 
(1963), Burch (1972), Clarke (1973, 1979). or better 
still, to all of these. 5. simile and 5. striatinutn 
are the most abundant species of Sphaerium and 
are the most frequently encountered, but in 
Pisidium the most abundant is the variable 
species P. casertanum (Poll) followed by P. com- 
pressum Prime and several other species. 

Sphaetium nitidum (Clessin) (Figs. 2, J-M) is 
up to 6 mm long, rounded anteriorly, posteriorly, 
and ventrally, and with centrally-located beaks. 
Fine concentric striae (more than 12 per mm) 
cover the shell and maintain their height and 
spacing up over the beaks. There is no radial 



ridge on the inside of the shell. The periostracum 
is shiny and pale yellowish-brown. 

Sphaerium occidentale Prime (Figs. 2, N-Q) is 
up to 7 mm long, also rounded anteriorly, 
posteriorly, and ventrally and with centrally- 
located beaks. The fine concentric striae (more 
than 12 per mm) which cover the shell are even 
finer near and over the beaks. A low, flat, radial 
ridge on the inside of the shell runs from the 
beak cavity to the central ventral margin. The 
periostracum is pale yellowish-brown to brown 
and dull or somewhat glossy. 

Sphaerium simile Say (Figs. 3, G-J), the largest 
Sphaerium in North America, ordinarily exceeds 
16 mm in length and may reach 25 mm. The shell 
is long oval, rather thin to fairly thick, and 




/*^^\ 









FIG. 2. Trophic lake-stage indicator species of Sphaeriidae. A-C, Pisidium rotundatum (USNM 595777, length 1.95 mm); D-H, 
Pisidium ventricosum (USNM 16U25. 1.85 mm): J-M, Sphaerium nitidum (USNM 216222. S.i5 mm): N-Q, Sphaerium occidentale 
(USNM iTiS.J2. 7.55 mm). 



182 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 




FIG. 3. TVnphic lake-stage indicator species of Sphaeriidae. A-C, Sphaerium striatinum (NMC 502S0. length 13.0 mm): D-F, 
Pisidium idahoense (NMC 327J,8. 7.1 mm): G-J, Sphaerium simile (NMC 1,5082, 118 tnm): K-P, Pisidium conventus (USNM 
363001. 3.0 mm). 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 183 



covered with coarse concentric striae (8 or fewer 
per mm near the center) which are more widely 
spaced over the beaks. The periostracum is 
brownish or yellowish, with concentric lighter 
and darker bands, and the interior of the shell is 
bluish. 

Sphaerium stiiatinum (Lamarck) (Figs. 3, A-C) 
is up to 14 mm in length, oval, and relatively 
thick and strong. It is covered by concentric 
striae (8 or less per mm) which are unevenly 
spaced and irregularly strong or weak in the 
same specimen, but are not weaker on the beaks. 
It is also brownish or yellowish, with concentric 
darker and lighter bands, and with a bluish in- 
terior. In juveniles, the dorsal margin is curved 
in 5. striatinum but straight in S. simile. 

Pisidium conventus Clessin (Figs. 3, K-P) is 
small (less than 3 mm long), variable in shape 
(ordinarily some specimens are trapezoidal), thin, 
fragile, suboval, not inflated, and with a dull 
glossy periostracum. The hinge plate is long 
(more than 3/4 the shell length), with cardinal 
teeth overhanging the edge of the hinge plate, 
and with lateral teeth thin and narrow and with 
the cusps (the highest parts) located near the 
outer ends. For further details see Heard, 1963. 

Pisidium idahoense Roper (Figs. 3, D-F) is 
large (for Pisidium), up to 12 mm long, but most 
specimens are closer to 8 mm. The shell is ovate, 
with a short dorsal margin, and with the surface 
covered by fine, concentric striae (15 or more per 
mm). These characters will distinguish P. ida- 
hoense from the other large species of Pisidium 
(P. adamsi, P. amnicum, and P. dubium). Al- 
though P. idahoense is characteristic of meso- 
trophic lakes throughout its range on the North 
American mainland, it occurs in eutrophic lakes 
on Prince Edward Island, Canada. 

Pisidium rotundatum Prime (Figs. 2, A-C) (and 
P. ventricosum Prime, Figs. 2, D-H) are both 
small (about 3 mm long) and more spherical in 
shape than most other Pisidium species. In P. 
rotundatum the height divided by the length 
(H/L) is .80 to .92 and the width divided by the 
length (W/L) is .70 to .76. In P. ventncosum 
(H/L) is .82 to 1.00 and (W/L) is .80 to .95. In P. 
rotundatum. the beaks are located almost central- 
ly or are posterior of center but in P. ven- 
tncosum they are far posterior. In the left valve 
of P. rotundatum the hinge plate between the 



cardinal teeth and the anterior lateral tooth is 
narrow and much longer than wide, whereas in 
P. ventricosum it is thick and short, i.e. about 
equally long and wide. P. rotundatum is 
characteristic of eutrophic water bodies and P. 
ventricosum occurs in both mesotrophic and 
eutrophic lakes. 

It is useful to remember that some small 
marine bivalve mollusks resemble sphaeriids and 
may be mistaken for them, and vice versa. This is 
especially important in the interpretation of 
fossil deposits. The various species of marine 
bivalves all possess unique hinge teeth and other 
differential characteristics, however, which can be 
observed by careful examination. See Abbott 
(1974) and included references for further in- 
formation on marine mollusks. 

It should be remembered that occasional 
specimens of most sphaeriid species may be found 
in all kinds of habitats. The presence of an in- 
dicator species is therefore only significant as a 
trophic lake-stage indicator if that species occurs 
in relative abundance. 

As one gains familiarity with Sphaeriidae, in- 
terpretation of trophic lake stages based on them 
becomes more practical. The shells of most species 
are variable, however, and the significant 
characteristics of the hinge teeth of Pisidium are 
minute and difficult to observe. It is therefore 
recommended that limnologists utilize for lake 
classification a larger suite of indicator species 
than that provided by the Sphaeriidae alone. 

ACKNOWLEDGMENTS 
I thank C. 0. Berg, G. L. Mackie, and J. 
Rosewater for useful suggestions, Ms. Cathy 
Lamb for laboratory assistance, and Mrs. Carolyn 
Gast for preparing the drawings. The photographs 
were supplied through the courtesy of the Na- 
tional Museums of Canada and the Smithsonian 
Institution. 

REFERENCES 

Abbott. R. T. 1974. American Seashells. Second Edition. Van 
Nostrand Reinhold Company, New York. 663 pages. 

Burch. J. B. 1972. Freshwater Sphaeriacean Clams 
(Mollusca:Pelecypoda) of North America. Biota of 
Freshwater Ecosystems Identification Manual No. 3. pp. i- 
viii + 1-33. United States Government Printing Office, 
Washington. 

Camp, M. J. 1974. Pleistocene Mollusca of three southeastern 
Michigan marl deposits. Sterkiana No. 56:21-64. 



184 THE NAUTILUS 



October 30. 1979 



Vol.94 (4) 



Clarke, A. H. 1973. The freshwater molluscs of the Canadian 

Interior Basin. Malarologia 13:l-.509. 
. (1980): The Freshwater Molluscs of Canada 

Special Publications, National Museums of Canada, Ottawa 

(in press). 
Gibson, G. G. 1967. Pleistocene non-marine MoUusca of the 

Richardson Lake deposit, Clarendon TowTiship, Pontiac 

County, Quebec, Canada. Sterkiana, No. 25: 1-36. 
Heard, W. H. 1963. The biolog>' of Pisidium (Neopisidium) 

conventus Qessin (Pelecypoda:Sphaeriidae). Papers uf the 

Michigan Academy of Science. Art^. and Letters i8:ll-S6. 
. 1965. Comparative life histories of North 

American pill clams (Sphaeriidae:ffeMf iwm). Malacologia 

2(3):,381-m. 



. 1977. Reproduction of fingernail clams (Sphaeri- 

idae :Sp/iaenum and Mitsadium). Malacologia 16(2):42M55. 

HerrinRtcm, H. B. 1962. A revision of the Sphaeriidae of 
North America (Mollusca:Pelecypoda). Miscellaneaus 
Publicatiiins, Museum of Zoology, University of Michigan, 
118: 1-74, 7 plates. 

Miller, Barry B. 1966. Five Illinoian molluscan faunas from 
the -southern Great Plains. .Vfo/ofo/of/ia 4 (l)L173-260. 

Taylor, D. W. 1957. Pliocene freshwater moUusks from Nava- 
jo County. Arizona. Jimmal of Rdeontology 31(3):654-661. 

Warner. D. J. 1968. Pleistocene Gastropoda of a lake deposit, 
Rimouski County. Quebec, Canada. Sterkiana. No. 31:1-14. 



URANIUM-SERIES AGES OF ECHINOIDS AND CORALS FROM THE UPPER 
PLEISTOCENE MAGDALENA TERRACE, BAJA CALIFORNIA SUR, MEXICO 

A. Omura W. K. Emerson T. L. Ku 

Department of E^arth Sciences Department of Invertebrates Department of Geological Sciences 

Kanazawa University American Museum of Natural History Universityof Southern California 
Kanazawa 920, Japan New York, NY 10024 Los Angeles. CA 90007 

ABSTRACT 

Nine ""Th/^'^U and "^Pa/^^^U dates on six coexisting corals (Porites califor- 
nica) and echinoids (Encope grandis) from the Magdalena Terrace, west coast of 
Baja California Sur, Mexico, average 116,50O±6,0O0 years (± one standard devia- 
tion). Based on this average, the newly named Magdalena Terrace may he cor- 
relative with the Nestor Terrace in the San Diego, California area and possibly 
with several other late Pleistocene terraces along the California coast thought to 
have been formed during a highstand of the sea 120,000 - 125,000 years ago. 
Although fossil echinoids contain uranium of secondary origin their ages are con- 
cordant with those of the coexisting corals and suggest that the uranium uptake 
occurred .^oon after the death of the organisms. 77!?.s. as well as the low "^Tli con- 
tent in both the living and fossil Encope analyzed suggests that a further in- 
vestigation of echinoids is warranted to examine their suitability .for 
geochronological studies with U-series nwclides. 



We report the ""Th/"''U and "■Pa/"'U dating 
on two samples of the stony coral Porites califor- 
nicn and four samples of the irregular echinoid 
Encope grandis from marine terrace sediments at 
Magdalena Bay (Bahia Magdalena) on the west 
coast of Baja California Sur. Mexico. The mean 
and standard deviation of the six "°Th/'^''U dates 
are 117,000 ± 7,000 years. The mean and standard 
deviation of the three "'Pa/"'U dates are 
115,000 ± 5,000. The two methods are in con- 



cordance, giving an average age for the nine 
dates on the six samples as 116,500 ± 6,(X)fl years. 
U-series dates exist for several terraces bordering 
southern California (summary in Ku and Kern, 
1974) and from Guadalupe Island (Isla Guada- 
lupe), some 400 km off Baja California Norte 
(Goldberg. 1965). Our dates are the first for 
Pleistocene terrace sediments from penisular Baja 
California. TVie radiometric dates now available 
for the richly fossiliferous deposits of Magdalena 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 185 



Ba.\' permit more precise regional comparisons of 
this fauna with those of chronologically related 
Pleistocene deposits dated previously. 

The present results suggest that Pleistocene 
specimens of echinoids, and possibly those of 
other echinodeiTns, are potentially datable by the 
U-series methods. This is significant in view of 
the general scarcity of specimens of coral in ter- 
race deposits. Echinoids, especially the disarticu- 
lated plates and spines of regular ones (sea 
urchins) and, to a lesser degree, the tests of ir- 
regular ones (sand dollare) are not uncommonly 
pi'eserved in terrace sediments. If reliable 
radiometric dates can be obtained from echinoids, 
the numerous terrace deposits of late Pleistocene 
age along the West American borderland and 
elsewhere throughout the world can be dated 
more precisely. 



1841, were collected from a Pleistocene terrace 
about 1.5 km north of the village of Puerto 
Magdalena (24°38'N, 112°09'W), on the east side 
of Santa Magdalena peninsula, Baja California 
Sur, Mexico, from The American Museum of 
Natural History [A.M.N.H.] locality F-6 
[ = California Academy of Sciences (C.A.S.) locali- 
ty 754]; see Figure 1. The samples analyzed with 
U.S.C. lab. nos. designated as AO-3, -4, -5 (Table 
1) are from A.M.N.H. locality F-6 collected on 
March 17, 1957 (Emerson, 1958). Those designated 
as AO-6, -7, -8 (Table 1) are from C.A.S. locality 
754, collected July 25. 1925 by G D. Hanna and E. 
K. Jordan (Jordan, 1936). 

The two Recent specimens (U.S.C. lab. no. 
AO-1, -2) of Encope grandis are from San Carlos 
Bay, near Guaymas, Sonora, Mexico (27°57'N, 
lli°04'W). 



SAMPLE LOCALITIES 

The coexistent fossil specimens, comprising of 
two samples of Pontes califomka Verrill, 1870 
and four samples of Encope grandis L. Agassiz, 



EXPERIMENTAL RESULTS 
AND DISCUSSION 
Table 1 summarizes analytical results of 
samples AO-1 through AO-8. Known quantities of 



Table 1. Radiometric and Age Data on Echinoids and Corals from Mexico 



Lab 
No. 


Materia 


1' Mineralogy 


U 
(ppm) 


Th 
(ppm) 




"«Th 
^^■'Th 


""Th 


"'Pa 5 


Age (10= 
""Th 


-^^Pa^ 


AO-1 


E.g.' 


High-Mg 
Calcite 


0.204 
±,003 


<0.02 


1.14 
±.02 


- 


<0.01 


<0.1 


<1 


<5 


AO-2 


E.g.= 


High-Mg 
Calcite 


0.293 
±.005 


<0.02 


1.14 
±.02 


- 


<0.01 


<0.1 


<1 


<5 


AO-3 


P.c- 


Aragoni te 


3.50 
±.08 


0.022 
±.007 


1.08 
±.02 


345 
±108 


0.656 
±.025 


0.892 
±.045 


116±8 


110^" 

-1 9 


AO-4 


E.g." 


High-Mg 
Calcite 


0.465 
±.008 


0.035 
±.003 


1.01 
±.02 


28.1 
±2.6 


0.667 
±.016 


0.906 
±.041 


119±5 


117*" 

-IB 


AO-5 


E.g." 


Low-Mg 
Calcite 


1.86 

±.04 


<0.02 


1.05 
±.02 


>300 


0.692 
±.025 


n.m. 


128±9 


n.m. 


AO-6 


P.c." 


Aragonite 


3.36 
±.12 


0.062 
±.006 


1.14 
±.03 


128 
±39 


0.663 
±.036 


n.m. 


118±12 


n.m. 


AO-7 


E.g." 


Low-Mg 
Calcite 


1.56 
±.04 


0.070 
±.010 


1.06 
±.02 


46.2 
±6.5 


0.632 
±.026 


n.n. 


108±8 


n.m. 


AO-8 


E.g." 


Low-Mg 
Calcite 


0.810 
.010 


<0.02 


1.08 
±.01 


>400 


0.647 
±.020 


0.910 
±.043 


113±6 


-19 


1 


E.G.: 


Encope grandis; P 


.c: Por 


-ites cal 


ifornica. 













Recent, dead-collected, beach specimen. 
Recent, live-collected specimen. 
Pleistocene specimens, 
n.m. : not measured. 



186 THE NAUTILUS 



October 30,1979 



Vol. 94 (4) 



232 U_ 228'J^ ^j^(J 233p^ ^,g^p ^gg^J ^g y\^\^ traCCfS Ih 

the analyses of the radioisotopes listed. The 
quoted errors (one standard deviation) are based 
on the counting statistical fluctuations only. 
Mineralogical identifications were done with 
x-ray diffraction techniques. In computing 
the ages, we assumed that "°Th and "'Pa were 
initially absent or present in negligible amounts 
and that samples acted as a closed system after 
incorporation of the radioisotopes. The half-life 
values used for ""Th and "'Pa are 75,200 years 
and 34,300 years, respectively. 

The assumption of negligible initial ""Th and 
"'Pa (Table 1) is suppf)rted by the observations 
that, firstly, "'•Th/"'Th values in the fossil 
specimens are very much higher than those 
values in natural waters or sediments, which are 
commonly 1 to 3, and secondly, modern specimens 
of E. yrandis show very low ^^°Th/"''U and 
"'Pa/"*U values of <0.1, as is the case for corals 
(Ku, 1968). The closed-system assumption is sup- 
ported by the concordancy checks between the 
"°Th/"^U- and "'Pa/"'U-" derived ages on three 
samples in which such checks were made (Table 
1). The validity of this assumption is alscj 
reflected in the agreement, within counting 
statistical error, of ages for the six coexisting 
fossil specimens. 

As the present study reports the first mea- 
surements on echinoids, a discussion of the data 
obtained is in order. The ""U/"' U ratios of 1.14 
in AO-1 and AO-2 are the same as that for 
uranium in sea water (Ku, et ai, 1977). Living E. 
'(innidis apparently incorporate about 0.2-0.3 ppm 
of uranium directly from sea water. Unlike coral, 
there appears to be a discrimination factor of 10 
to 1 in favor of Ca to U in the uptake of these 
two elements from sea water by the organism. 
With the exception of the echinoderm teeth, the 
hard tissue of echinoderms is known to be 
originally composed of calcite containing several 
per cent Mg (Chave, 1954; Schroeder et al., 1969). 
This is the case for samples AO-1, -2, and -4. 
Because high-Mg calcite is metastable under sur- 
face conditions, its transformation to low-Mg 
calcite could provide conditions condusive to ex- 
change of radionuclides with thase in the 
surroundings— conditions similar to the conver- 
sion from aragonite to calcite for coral. Data on 
samples AO-5, -7. and -8 suggest that during the 



transformation to low-Mg calcite, significant 
amounts of uranium may have entered the 
echinoid skeletal tests with little or no accompa- 
nying thorium isotopes. For sample AO-4, the 
slightly higher-than-modem U value (ppm) fur- 
ther suggests that limited addition of uranium 
could have also occurred before the transforma- 
tion. This secondary uranium added to the sam- 
ple is largely of non-marine origin, judging from 
the "''U/"«U value of 1.01 ± .02 (oceanic uranium 
would decay from 1.14 to 1.10 in about 120,tKX) 
years). 

From the above discussion, one sees some 
parallel between E. gy-andis and mollusks in 
terms of open system for secondary uranium up- 
take in fossil specimens. However, the present 
results show two encouraging aspects of dating E. 
grandvi: (1) The concordant ages obtained here 
suggest that the open-system episode must have 
been brief and limited to a period very close to 
the death of the organism. (2) There is evidence 
for n^ligible presence of initial and extraneous 
"°Th and "'Pa in the samples analyzed (Table 1). 
These favorable conditions have been found in 
mollusks, but they are not common (Kaufman, et 
al., 1971). Thus for echinoids, one needs to deter- 
mine how commonly these conditions occur and 
what criteria are required to distinguish them. 
These questions cannot be answered from the pre- 
sent limited number of analyses. Further studies 
of echinoid tests to evaluate their suitability for 
U-series dating are warranted. 

MAGDALENA TERRACE-OCCURRENCE, 

FAUNAL ASSEMBLAGE 

AND CORRELATION 

The terrace represented by A.M.N. R locality 
F-6 (Fig. 1) extends along the shore at a max- 
imum elevation of approximately 6 meters above 
sea level. The fossils are most numerous in 
sediments of poorly sorted sand and angular ig- 
neous rocks exposed along the shore at the high 
tide level to an elevation of 1.5 to 1.8 meters. The 
fossiliferous sand is locally overlain by to 4.6 
meters of non-fossiliferous alluvial cover. A con- 
glomerate resting on the terrace platform, which 
cuts into the basal igneous bench-rock, is exposed 
at the level of the present beach on the apparent- 
ly correlative terrace remnants that are pre- 
served along the shore for about 1.5 km south of 



Vol. 94 (4) 



October 30, 1979 



THE NAUTILUS 187 



AREA OF . 

IHOtX MAP \^ N 




FIG. 1. Iiidei- map afthe Magdalena Bay - Almejiui Bay area ofBnja California Sur. Mexico, showing Pleistocene fossil localities (F-5, 
F-6 on Santa Magdalcna peninifula: F-7. F-S on Santa Margarita Island) described in the text. 



Puerto Magdalena village (Figure 1, A.M.N.H. 
locality F-5 = C.A.S. locality 982). This con- 
glomerate and the terrace platform are not ex- 
posed at locality F-6. According to Hanna (1925), 
these terrace remnants represent the beach-line 
existing at the time of uplift of the igneous and 
metamorphic rocks which form the higher terrain 
behind the village, and this tectonic event re- 
sulted in the closure of the northern entrance 
to Magdalena Bay. A terrace similar to that at 
Puerto Magdalena is exposed north and south of 
the village of Puerto Cortes on the eastern shore 
of adjacent Santa Margarita Island (Isla Santa 
Margarita), which faces Almejas Bay (Bahia 
Almejas), see Figure 1. This terrace extends 
about 6.5 km along the shore south of Puerto 
Cortes at a maximum elevation of about 4.6 m (at 
A.M.N.H. locality F-7) and continues north of the 
village at the same height for about 1.2 km 
(Figure 1, A.M.N.H. locality F-8=C.A.& locality 
932). The terraces exposed at the localities on 
Santa Margarita Island are cut into basal igneous 



rocks (0-1.5 m in thickness) and are overlain by 
conglomerates (.5 to 6 m), fossiliferous sand peb- 
bles (.5 to 1.2 m), and pebbly soil cover (.5 and 1.2 
m). The terrace appears to be tilted slightly to 
the northwest, as is the terrace on the Santa 
Magdalena peninsula. These topographic features 
are here designated the Magdalena Terrace, with 
the type locality restricted to the section exposed 
at A.M.N.H. locality F-6 on the Santa Magdalena 
peninsula. 

The presence of well-preserved metazoan in- 
vertebrate fossils, mostly mollusks, in terrace 
sediments in the vicinity of Magdalena Bay has 
long been known. Hinds (1844) was the first to 
report mollusks "... embedded in the fossiliferous 
cliffs which surround a portion of the Bay of 
Magdalena." Dall (1918), Smith (1919), Jordan 
(1924), and Hanna (1925) considered the age of 
these terraces to be Pleistocene, based on faunal 
evidence. Jordan (1936) listed a total of 442 
species-group taxa, including 4 echinoderms, 1 
coral, and 337 mollusks, from three locations in 



188 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



Magdalena Bay (C.A.S. localities 754, 932, and 
982). He concluded that "...the beds should be cor- 
related with the warm Upper San Pedro, or Up- 
per Quaternary" (of Arnold (1903) in the Los 
Angeles Basin, now referable to the upper 
Pleistocene Palos Verdes Sand). The Magdalena 
Bay assemblage is the largest Pleistocene in- 
vertebrate fauna described from Pacific Baja 
California (Emerson, 1956; Gastil et ai., 1975) 
and, in western North America, it is second in 
size only to the assemblages reported from 
Newport Bay, California, where nearly 500 
species of metazoan invertebrates are recorded 
from late Pleistocene deposits (Kanakoff and 
Emerson, 1959). 

The fauna! constituents of the Magdalena Ter- 
race are essentially modem in composition, con- 
taining a nearly equal mixture of Panamic and 
Califomian Provincial faunal elements, together 
with wide-ranging, eurytopic taxa. The metazoan 
invertebrates living at the present time in 
Magdalena Bay also represent a blending of these 
faunal components, with perhaps a diminution in 
the ratio of the warm water (Panamic element) 
to the temperate water components (Califomian 
element). The Panamic element is present in 
similar terrace deposits occurring northward 
along the continental borderland. This southern, 
warm-water element diminishes in numbers 
rapidly in Pleistocene assemblages north of Viz- 
caino Peninsula (27°50'N., 115°5'W) and is a 
minor faunal component in the San Diego and Los 
Angeles embayments, where wide-ranging and 
cooler faunal elements dominate (Emerson, 1956). 
Changes in the composition of these assemblages 
have been largely ascribed to alternating 
hydroclimatic regimes that accompanied the late 
Pleistocene oscillations of the continental ice 
sheets (cf. Valentine, 1955, 1961; Kanakoff and 
Emerson, 1959; Addicott and Emerson, 1959; 
Kennedy et al.. 1979). Because species-level ex- 
tinctions in faunas have been negligible during 
the late Pleistocene and tectonic changes in the 
coastal configuration have locally obscured the ef- 
fects of eustatic changes in sea level during this 
period, traditional stratigraphic and paleontologic 
methods do not permit absolute temporal and 
regional correlations of these terraces (cf. 
Durham and Allison, 1960; Ku and Kern, 1974). 
The U-series ages obtained here suggest correla- 



tion of the Magdalena Terrace with the Nestor 
Terrace in San Diego and similar terraces in the 
region, formed during a highstrand of the sea ap- 
proximately 120,000 yrs. ago (Ku and Kem, 1974) 
during the early Sangamon (isotopic stage 5e of 
Shackleton and Opdyke, 1973). More precise cor- 
relation must await absolute dating of additional 
regional deposits. 

ACKNOWLEDGMENTS 
Peter U. Rodda, Chairman of the Department 
of Geology, California Academy of Sciences, 
generously contributed fossils for dating (C.A.S. 
locality number 754). William E. Old, Jr. of the 
Department of Invertebrates, American Museum 
of Natural History kindly provided technical 
assistance in the preparation of the manuscript. 
We are indebted to George L. Kennedy, U. S. 
Geological Survey, Menlo Park, California and 
Leslie F. Marcus, City University of New York, 
for critically reading the manuscript. The 
radiochemical analyses were done at the Univer- 
sity of Southern California supported by National 
Science Foundation grant EAR 77-13680 to T. L. 
Ku and W. H. Easton, Contribution no. 394, 
Department of Geological Sciences, University of 
Southern California. 



LITERATURE CITED 
Addicott. W. 0. and W. K. Emerson. 1959. Late Pleistocene 

invertebrates from Punta Cabras. Baja California. Mexico. 

Amer. Mus. Novitates. no. 192.5. 33 p. 
Arnold, R. 1903. The paleontolog>' and stratigraphy of the 

marine Pliocene and Pleistocene of San Pedro, California. 

Calif Acad. Sci. Mem. 3:1-419. 
("have, K. E. 19.54. Aspects of the biogeochemistry of 

magnesium: 1. Calcareous marine organisms. Jour. Geol. 62: 

587-599. 
Dall, W. H. 1918. Pleistocene fossils of Magdalena Bay, Lower 

California, collected by Charles Russell Orcutt. Tfte 

Afa?rfi7i(.s 32:23-26. 
Durhiun, .1. W. and E. C. Alli-son. 1960. The geologic history of 

liija California and its marine faunas. Systematic Zool. 

9:47-91. 
Emerson. W. K. 19.56. Pleistocene invertebrates from Punta 

China, Baja California. Me.xico, with remarks on the com- 
position of the Pacific Coast Quaternary faun;is: .■\mer. 

Mus. Bull. 1I1:31.5-:M2. 
1958. Results of the Puritan - American Museum 

of Natural History Expedition to western Mexico. 1. 

General account. Amer. Mus. Novitates no. 1894, 25 p. 
Gastil, R. G., R. P. Phillips, and E. C. Allison. 197.5. Recon- 
naissance geology of the State of Baja California. Geol. Soc. 

Amer. Mem. 140, 170 p. 



Vol.94 (1) 



October:?!), 1979 



THE NAUTILUS 189 



Goldberg, E. D. 1965. An observation on marine sedimentation 
rates during the Pleistocene. Limnol. and Oceanog. Suppl.. 
10:R 125-128. 

Hanna, G D. 1925. Ebcpedition to Guadalupe Island. Mexim. in 
1922. Prnc. Calif. Acad. Sci., ser. 4. 14:217-275. 

Hinds, R. B. 1844. (On new species of Terebra). Proc. Zool. Soc. 
London, pt. 11, "for 1843": 149-168. 

Jordan, E. K. 1924. Quaternary and Recent molluscan faunas 
of the west coast of Lower California. Southern Calif. Acad. 
Sci. Bull. 23:145-156. 

1936. The Pleistocene fauna of Magdalena Bay, 

Lower California. Contr. Dept. Geol. Stanford Univ. 1:103 
-173. 

Kanakoff, G. P. and W. K. Emerson. 19.59. Late Pleistocene in- 
vertebrates of the Newport Bay area, California. Los 
.Angeles Co. Mus. Contrib. Sci., no. 31: 47 p. 

Kaufman, A., W. S. Broecker, T. L. Ku. and D. L. Thurber. 
1971. The status of U-series methods of mollusk dating. 
Geochim. Cosmochim. Acta 35:1155-11&3. 

Kennedy, G. L.. K. R. Lajoie, and J. F. Wehmiller. 1979. Late 
Pleistocene and Holocene zoogeography. Pacific northwest 
coast. Abstracts, Cordillian Section, Abstracts with Pro- 
grams, Geol. Soc. Amer. 11(3):87. 



Ku, T. L. 1968. Pa."' method of dating corals from Barbados 

Island. Jour. Geophys. Research 73:2271-2276. 
Ku, T. L. and J. P. Kern 1974. Uranium-series age of the up- 
per Pleistocene Nestor Terrace, San Diego, California. Geol. 

Soc. Amer. Bull 85: 1713-1716. 
Ku, T. L, K. G. Knauss and G. G. Mathieu. 1977. Uranium in 

open ocean: Concentration and isotopic concentration. 

Deep-Sea Res. 24: 1005-1017. 
Schroeder, J. H.. E. K. Dwornik and J. J. Papike. 1969. 

Primary proto-dolomite in echinoid skeletons. Geol. Soc. 

Amer. Bull. 80:1613-1616. 
Shackleton, N. J. and N. D. Opdyke. 1973. Oxygen isotope and 

palaeomagnetic stratigraphy of equatorial Pacific core 

V28-238: Oxygen isotope temperatures and ice volume on a 

W and W year scale. Quat. Res. 3:39-55. 
Smith, J. P. 1919. Climatic relations of the Tertiary and 

Quaternary faunas of the California region: Proc. Calif. 

Acad. Sci., ser. 4, 9: 123-17.3. 
Valentine, J. W. 19.55. Upwelling and thermally anomalous 

Pacific Coast Pleistocene molluscan faunas. Amer. Jour. Sci. 

253: 462-474. 
. 1961. Paleoecologic molluscan geography of the 

Californian Pleistocene. Univ. Calif. Publ. Geol. Sci. 34: 

1309-442. 



THE NAIAD FAUNA OF LAKE SPRINGFIELD, ILLINOIS: 
AN ASSESSMENT AFTER TWO DECADES 

Walter E. Klippel and Paul W. Parmalee 

Department of Anthropology' 
University of Tennessee, Knoxville, Tennessee 37916 



ABSTRACT 

A sui-vey of the naiad fauna uf Lake Springfield during 195S pniduccd nine 
species of freshwater mussels. A second survey of the identical collection localities, 
conducted in 1977. produced the same nine species. Patterned quantative changes 
in the fauna were observed. Qualitative changes have resulted from the introduc- 
tion of four previously unrecorded species. Variations in the naiad populations 
have been discussed in terms of observed changes in other aiiificinlly formed lentic 
habitats as well as unimpounded fluvial systems. 



Nearly two decades after the construction of 
Lake Springfield during 1935, a survey of the 
lake's naiad fauna was, conducted and reported 
by the junior author (Parmalee 1955). The lake, 
situated in Sangamon County in central Illinois, 
is fed by Lick and Sugar creeks, has a surface 
area of 17.6 km^ and roughly 90 km of shoreline. 
At the time of the 1953 survey central Illinois 
had suffered several months of below average 



rainfall and by October, 1953, the level of Lake 
Springfield fell to an average (169.07 m MSL) 1.62 
m below normal pool (170.69 m). 

The_exposed shoreline of the relatively shallow 
lake (X depth = 4.57 m) gave rise to the survey 
of stranded freshwater mussels along the waters 
edge. Nine hundred and eighty-seven specimens 
representing nine species were recovered from 20 
different collecting stations (Fig. 1). The area 



190 THE NAUTILUS 



October 30. 1979 



Vol.94 (4) 




FIG. 1. Lake Springfield, Rlinois, shoviing stations where 
tuiiads were collected in 195.i and 1977. 

sampled (4x50 yr.) at each loci was about 167.4 m, 
(200 yr^), bringing the total area collected to 3346 
m^ and providing a mean density of .295/m^ 

Quadnda quadnda (Rafinesque, 1820) occurred 
in greatest abundance (48%), followed by Lep- 
todea laevissima (Lea, 1830)— 22%, Lasmigona 
complanata (Barnes, 1823)— 11%, Ligumia riasutn 
(Say, 1817)-11%, Anodmta grandis (Say, 1829) - 
6%, Amblema plicata (Say, 1817)-1%, and 
Anodmta imbecilis (Say, 1829)— 1%. Fusconaia 
flava undata (Barnes, 1823)— 1% and Arddens 
confragosnLR (Say, 1829)— 1% were represented by 
only one specimen each (Parmalee 1955:32). 

During 1976, slightly over two decades after 
the low water of 1953, central Illinois was once 
again subjected to below average rainfall which, 
by early winter, had left Lake Springfield 1.56 m 
(169.13 m MSL) below normal pool. The water 
level continued to drop until February, 1977, 
when it finally reached a low of 168.80 m MSL. 

By March, 1977, the snow cover that had 
blanketed the otherwise exposed shoreline had 
melted, and during the next ten days a second 
survey of the 20 loci collected during 1953 was 
completed. During this period the lake level 
ranged from 169.13 m MSL to 168.95 m MSL (Fig. 
2a) and was an average 169.19 m MSL; a mean 
level only 12 cm higher than the mean level for 



October, 1953, when the initial sun^ey was con- 
ducted. By May, 1977, the lake had again at- 
tained a normal pool (Fig. 2b). 

Distances of 50 m were marked off along the 
waters edge at 18 of the 20 stations and collec- 
tions of all shells with one dimension larger than 
1.5 om were made for a distance of 4 m back 
from the waters edge. In two instances (Stations 9 
and 23) the areas collected were extended to 100 
m long by only 2 m wide because of heavy grass 
and brush cover that occurred within 3 to 4 m of 
the waters edge. Both of these stations are at the 
headwaters of the lake where the water line 
begins to take on characteristics more like the 
btinks of Sugar and Lick creeks than the shore- 
line of Lake Springfield. Although the dimensions 
(100x2 m) differ from areas established at the 
other 18 stations (50x4 m), even,' attempt was 
made to collect the same amount of surface area 
at all stations, i.e. 200 m^. It should be noted at 
this point that the areas collected during 1977 
(200 m^) are roughly 20 percent larger than the 
areas collected in 1953 (200 yr^ = 167.3 m^. 

A total of 2177 paired valves were recovered 
from the 20 stations during 1977. The area 
sampled at each station was 200 m^ bringing the 
total area collected to 4000 m^ and providing a 
mean density of .544/m^ or almost twice as many 
specimens per unit area as found at the same loci 
during 1953. 

Qualitative Changes in the Naiad Fauna 

Qualitative changes have occurred in the lake's 
fauna as a result of the introduction of four new 
species (Carunndina paira (Barnes, 1823), Tmn- 
rilla truncata Rafinesque 1820, Obliqrmria reflexa 
Rafinesque 1820 and Corbinda manilcns-is Philip- 
pi). There has also been an overall increase in the 
lake's naiad fauna of roughly ten percent per 
unit area as well as statistically significant quan- 
tative changes among the nine original species. 
Unfortunately the myriad of unmonitored, inter- 
related factors responsible for the observed 
changes cannot be fully delineated post de facto. 
but there are some patterned variations that can 
be discussed. 

The nine original species (1953) constitute 1296 
of the total 2177 specimens recovered in 1977. 
When these primary species are considered sep- 
arately (n = 1296), the naiad density per unit area 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 191 



is only slightly greater (.324/m^) than that found 
during the first survey (.295/m^). Increases in the 
mussel fauna are restricted to as few as seven 
stations (i.e. 2, 5, 6, 9. 10, 12, and 15) situated 
along the main body of the lake (Fig. 1) where in- 
creases per unit area by station range from 71 
percent to 204 percent. Density was nearly the 
same per unit area at station 16 (i.e. < 2 percent 
change) while densities per unit area at the re- 
maining 12 stations decreased rather markedly. 



The upper reaches of the lake and the heads of 
many of the inlets have undergone considerable 
aggradation through siltation. This phenomenon 
was readily apparent when collections were made 
in 1977. The substrate at stations 4 and 13 
(inlets), 17, 18, 19 and 20 (upper reaches of lake) 
consisted of poorly consolidated silty clay loams 
and were difficult to collect without sinking 
waist deep in "muck". Also, the color of these ag- 
grading deposits was noticeably darker (Table 



TABLE 1. Frexhwatfr ninsscl.': nrorcrrd front tiirntij statians alutui the expiised shiireUiic of Lake Springfield. Iltindia. diiriiiy 
1953 and 1977. 



O I. 

— a> 



1 2 '3 

■-J tj 'op 



.3,2 2, 2:i 

?S 1^ I'S 

11 §2 i-f 

Of O- ^ a ^ -rf 



.3 § .3.2 



t 

a a, « 

■ri ■a u 

fc « -J •.» 

■-■3 ,0 a. 



!l 5 






1 


ne,ne,se,se of Sec. 
12; T15N; R5W (SE)* 


lOYR 5/4 


1953 
1977 




17 
8 










4 


18 
15 




4 


57 


18 
76 


2 


nw.se, sw,ne of Sec. 
19; T15N; R4U (NC) 


lOrR 4/4 


1953 
1977 




105 






1 


3 
3 




5 

115 




2 18 


15 


5 
150 


3 


nw,nw,se,se of Sec. 
14; T15N; R5U (NC) 


lOVR 4/4 


1953 
1977 


1 


26 
25 


13 


2 


11 
3 


15 

7 


25 


85 
57 


2 


18 


16 


85 
93 


i 


nw,ne,nw,sw of Sec. 
24; T15N; R5W (NC) 


lOYR 3/2 


1953 
1977 


1 


26 

17 


11 


2 
1 


8 


18 
13 


17 


81 
45 


3 


18 


27 


81 
93 


5 


se,ne,nw,ne of Sec. 
25; TISN; R5W (NC) 


lOrR 4/2 


1953 
1977 




28 
26 


24 


1 


5 

1 


12 
24 


33 


52 

109 


3 


59 


26 


52 

197 


6 


se.se, sw,sw of Sec. 
19; T15N; R4W (NC) 


lOYR 5/4 


1953 
1977 




4 
18 






2 


3 

5 


11 


16 
37 




6 11 


223 


16 
277 


7 


se,sw,sw,se of Sec. 
19; T15N; R4W (NC) 


lOYR 4/4 


1953 
1977 




78 
22 






3 


6 
6 




96 
32 




2 3 


70 


96 

107 


3 


sw,nw,nw,sw of Sec. 
30; TISN; R4W (NC) 


lOYR 5/4 


1953 
1977 


2 


25 
23 






10 


10 

3 




54 
30 




3 23 


48 


54 
104 


9 


sw,nw,se,se of Sec. 
36; nSN; R5H (NC) 


lOYR 3/1 


1953 
1977 




20 
65 




I 


3 


8 
5 




36 

74 




17 


5 


36 
96 


10 


ne,nw,sw,se of Sec. 
35; T15N; R5W (NC) 


lOTR 3/3 


1953 
1977 




12 

174 


17 


1 
4 


16 


29 
48 




68 

249 


4 


24 


75 


68 
353 


U 


se,se,nw,sw of Sec. 
36; T15N; R5U (NC) 


lOYR 3/3 


1953 
1977 


1 


33 
16 








5 

3 




45 
21 




7 


3 


45 
31 


12 


ne,sw,se,se of Sec. 
35; TISN; R5U (NC) 


lOYR 3/3 


1953 
1977 


2 


26 

203 




3 


5 


21 
14 




60 
231 


1 


26 


10 


60 
268 


13 


sw,se.se,ne of Sec. 

2; T14N; R5U (NC) 


lOYR 3/1 


1953 
1977 




21 
2 




1 


3 


2 
3 




34 
10 




I 


4 


34 

15 


14 


ne,ne,sw,nw of Sec. 
2; TUN; R5H (C) 


lOYR 4/3 


1953 
1977 




16 
33 




1 


12 

1 


13 

5 


4 


49 
41 




11 


1 


49 
53 


15 


sw,rTW,ne,nw of Sec. 
16; T14N; R5W (C) 


lOTR 3/3 


1953 
1977 


6 


75 




1 
1 


6 
2 


7 
10 


10 


30 
96 


1 


7 


1 


30 
105 


16 


sw,nw,nw,sw of Sec. 
3; T14N; R5U (C) 


lOYR 3/2 


1953 
1977 


2 


25 
44 




1 


9 

3 


13 
8 




52 

61 




6 


12 


52 

79 


17 


nw.sw.se.nw of Sec. 
32; T15N; R5U (C) 


lOYR 3/1 


1953 
1977 




14 
10 


11 


1 


3 


13 
9 




31 
31 


1 




5 


31 
37 


18 


ni5,ne,sw.sw of Sec. 
30; T15N; R5W (C) 


lOYR 3/1 


1953 
1977 




30 




2 




5 
2 


1 


39 
4 








39 
4 


19 


nw,nw,nw,sw of Sec. 
9; T14N; R5W (C) 


lOYR 3/1 


1953 
1977 




54 

7 


12 
12 




13 


21 
6 




100 
25 








100 
25 


20 


sw,5w,se,sw of Sec. 
34; T15N; R5W (C) 


lOYR 3/2 


1953 
1977 




17 

1 




4 


4 


9 
3 


5 


36 
12 






2 


36 

14 



•Determined from 7.5 minute UbGS quadrangles: (SE) ■ Springfield East; (NC) - New City; (C) - Chatham. 



192 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



1-lOYR 3/1, 3/2) than substrates at most other 
stations where yellowish brown and brown soils 
(primarily Hickory, Clinton, and Elco series— as 
depicted on advance soil sheets for Sangamon 
County) are eroding from the former valley walls 
of Sugar Creek (Table 1). Aggrading deposits 
transported into the lake from the nearly black 
upland prairie soils are very dark gray (lOYR 
3/1— Munsell) to very dark grayish brown (lOYR 
3/2) and consistently produced fewer naiads per 
unit area (X.ll/m^) than were found during 1953 
(X.32/m^). The relatively undiluted herbicides 
and/or pesticides, and large quantities of smoth- 
ering silt particles that settle out when they 
reach the sluggish waters of the lake have prob- 
ably contributed to this decrease in primary 
naiad density at these stations. 

Quantative changes among the primary species 
have also taken place over the past two decades. 
A chi square conducted on the 1953 and 1977 
populations (Table 2) clearly shows that there 
have been significant quantative changes in the 
naiad fauna (X^ = 202, df = 8. p .< .001). Q. 
quadrula, A. grandis and A. imbecUis occurred in 
greater frequencies than expected during 1977 
while L. cotnplanaUi, L. laevissima, A. plicata, 
and L. nasuta have decreased. Variation in oc- 
currence of L. complanata, Q. quadrula. L. 
/aem,s('»(a, A. plicata and L. natiuta contribute 
the greatest respective amounts to the high chi 
square value. 

A comparison of the combined assemblages 

TABLE 2. Ncdad fauna recorded for Lake Springfield during 
195J compared to the same specien recovered in 1977. 





total naiad 
fauna (1953) 


partla 
fauna 


1 naiad 
(1977) 




naiad epecles 


fo 


fe 


fo 


fe 


total 


Anblenu plicata 


14 


6.5 


1 


8.5 


15 


F^i.tninnm tlni'it midiitu 


1 


0.9 


I 


1.1 


2 


Quadrula quadrula 


472 


581.9 


874 


764.1 


1346 


Anodonta grtmdie 


63 


80.4 


124 


106.1 


187 


Anodanta vnbecilie 


7 


U.7 


20 


15.3 


27 


Arcidana oonfragoBUB 


1 


0.9 


I 


1.1 


2 


Latmigoruz acmplanata 


HI 


53.6 


13 


70.4 


124 


Leptodsa latvieeina 


213 


168.6 


177 


221.4 


390 


ligumia naeuta 


105 


82.2 


85 


107.9 


190 


Total 


987 




1296 




2283 



from the heads of inlets and upper reaches of the 
lake (i.e. stations 4, 13, 17, 18, 19 and 20) for the 
1953 and 1977 populations has been made by con- 
structing a contingency table similar to that in 
Table 2. At these loci A. grandis. A. imbecilis and 
L. laevissima occurred in greater frequencies 
than expected during 1977 while Q. quadnda. L. 
aiinplanata, L. nasuta and .4. plicata occurred in 
fewer numbers than expected. Even when the "no 
zero cell' requirement is fulfilled and .4. plicata 
and L. complanata are excluded (including only 
Q. quadrula, A. grandis. A. imbecilis. L. 
laevis.Kim(i, and L. nasuta). a chi square shows a 
statistically significant difference between 1953 
and 1977 population (X^ = 33, df = 4, p < .001). 

All three of the species that occurred in 
greater frequencies than expected are known to 
be more tolerant of mud substrates and lentic 
waters than many of the species that occur in the 
lake (Parmalee 1967:47, 48. 74). This observation 
tends to substantiate our previous supposition 
that naiad populations at these loci are being in- 
fluenced by siltation, as does the fact that Q. 
quadrula recovered from these areas are all 
mature individuals generally over five years of 
age. 

By way of comparison we have combined the 
assemblages at the seven stations on the main 
body of the lake that showed an increase mussel 
density per unit area (i.e. Stations 2, 5, 6, 9, 10, 
12, and 15) between 1953 and 1977. A contingency 
table shows that Q. quadrula. A. grandis and .4. 
imbecilis occur in greater numbers than expected 
while the other six primar>' species occur in a 
lower frequency than expected. A chi square on 
eight of the nine species (excluding A. plicata 
since none was found during 1977) shows the two 
I»pulations to be significantly different (X^ = 
235 df = 7: p < .001). These species are the same 
three that occurred in greater frequencies than 
exj^ected when all 20 stations were combined and 
1953/1977 samples were compared. A similar ma- 
nipulation of mussel counts from remaining sta- 
tions, i.e. those with decreased naiad density but 
not on the upper reaches of the lake or at heads 
of inlets, show changes in the same direction that 
other stations on the main body of the lake dis- 
play. 

Despite the lower naiad densities at these sta- 
tions, Q. quadrula, A. grandis and A. imbecilis 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 193 




FIG. 2. Lake Springfield. Illitmx at Station 13 shoiring ex- 
posed svbstmte near the head of an inlet during March 1977. 
Water level is at 169 in MSL 

occur in greater frequencies than expected while 
the remaining species occur in fewer numbers 
than would be expected if the populations had 
undergone no change over the past two decades. 

Qualitative Changes in the Naiad Fauna 

Four species of freshwater mussels recovered 
during 1977 were not found in the lake during 
the 1953 survey. Of the four species established 
since 1953, C. manilensis was found in greatest 
frequency. It made up 28 percent of the total 
specimens recovered during the 1977 survey and 
was second in abundance only to Q. quadrula. 
Had all specimens of the Asiatic clam been col- 
lected, they would have been quantitatively the 
most significant naiad in Lake Springfield. Lit- 
erally thousands of C. manilensis were not col- 
lected because they were less than 15 mm in 
diameter. In fact, the lower limit of 15 mm was 



established after the first station was visited as 
the task of collecting all Corbicula was found to 
be nearly impossible given the amount of time 
available for the second survey. 

Corbicula manilensis was introduced into the 
fluvial systems of North America as late as 1938 
and has since spread to most major drainages in 
the United States (Sinclair 1971). The environ- 
mental conditions this freshwater clam is able to 
tolerate in Illinois are varied but as late as the 
mid 1960s it was not found in the Mississippi 
drainage above Carlo in Illinois (Parmalee 
1967:95). However, over the past ten years the 
species has become established in the Illinois 
River (Thompson and Sparks 1977:34) and the 
major reservoirs of the Sangamon River drainage 
(e.g. Lake Springfield, Lake Decatur, Sangchris 
Lake) in central Illinois. In some drainages this 
species has been found to exceed 269,000/M^ in 
density and in instances has become so numerous 




FIG. 3. Lake Springfield, Illinois, at Station IS (inlet) during 
May. 19 77. Water level is at normal pool (1 70. 69 m MSL). 



194 THE NAUTILUS 



October 30, 1979 



Vol. 94 (4) 



as to pose problems at power generating and 
water filteration installations (Sinclair 1971). 

Three species of naiads (i.e. 0. reflexa. C. par- 
va, and T. tntncataj endemic to the Mississippi 
River drainage have also become established in 
Lake Springfield since the initial survey. All 
three species were known to exist in the Sanga- 
mon River drainage at the time of the 1953 
survey. 0. reflexa and T. (nnicata were reported 
common in the South Fork of the Sangamon not 
far from the lake, and an abundant population of 
T. tnmcata and C. jxirm was noted observed in 
Lake Decatur (Parmalee 1955:31) just upstream 
from Lake Springfield in the Sangamon River. It 
was speculated at the time of the 1953 survey 
that these species were either not present in 
Sugar Creek prior to its impoundment or that 
they were primarily lotic species that were not 
able to adapt to the man-made lentic habitat 
formed by Lake Springfield. 

Results of our 1977 survey clearly demonstrate 
that these three, especially 0. reflexa. are capable 
of maintaining viable populations in a man-made 
reservoir like Lake Springfield. The fact that over 
3300 M^ was systematically collected at 20 dif- 
ferent loci and that considerably more shoreline 
was sporadically surveyed (but not collected) and 
none of these naiads were found during 1953 
argues strongly for a more recent establishment 
of the species. Live specimens of 0. reflexa. 
utilized in another study (Parmalee and Klippel 
1974), were collected at Station 9 in August 1971; 
several individuals were between five and six 
years of age, which indicates this species had 
become established in the lake at least by 1965— 
and probably earlier. In contrast, C. manilenms 
was not present at this same station as late as 
spring 1973. 

The means by which these mussels could have 
been introduced are numerous, but two of the 
most likely avenues known to us are: 1) their in- 
troduction as glochidia with fish (primarily, but 
not exclusively, white bass) obtained from other 
fluvial systems in Illinois and placed in Lake 
Springfield by the Illinois Department of Conser- 
vation during 1951 and 1974, or 2) through the 
emergency water supply system that was estab- 
li.shed by City Water, Light, and Power shortly 
after the low water of 1953. This system consists 
of a canal that was excavated from a dividing 



dam along the east shore of the lake to nearby 
Horse Creek. Water from Horse Creek flows in 
the canal to the dividing dam from where it is 
pumped into the lake. According to City Water, 
Light, and Power records, the pumping facility 
was operated for a short period after its comple- 
tion in 1956 and again during 1976 and 1977 
when as many as 900 million gallons per month 
were pumped from the canal into Lake Spring- 
field. Either small fish infested with glochidia 
and/or glochidia suspended in the water may 
have been carried through this pumping facility. 

Regardless of how these three species were in- 
troduced they all seem to have become well 
established and are fairly widely distributed. (). 
reflexa was the third most numerous species 
recovered during the 1977 survey. It was only 
outranked in frequency by Q. qitadnda and C 
manilensw and was nearly as ubiquitous as the 
first and second ranked species (Table 1). 0. 
reflexa is noticeably absent and/or in low fre- 
quencies along the upper reaches of the lake and 
at the heads of inlets (e.g. Stations 13, 17, 18, 19, 
and 20). In general, 0. reflexa occurred in 
greatest frequencies at those same stations where 
the primary species were found in increased den- 
sity per unit area during 1977 (e.g. Stations 2, 5, 
9, 10, and 12). 

C. parva and T. tntncata were the eighth and 
ninth respective most numerous of the 13 species 
recovered. C. parva was found at and near rallec- 
tion stations throughout the lake while T. trun- 
cata in sampling strata were exclusively 
restricted to the east shore of the main body of 
the lake (e.g. Stations 2, 6, 7, and 8). At least 20 
additional T. truncata were observed outside the 
sampling loci at these stations but in only one in- 
stance was the species observed along any other 
portion of the lake. This location was approx- 
imately 90 meters outside the area collected at 
Station 5 which is also along the lower portion of 
the main body of Lake Springfield but on the 
west shore. Whether the present low population 
number is a result of what appears to be a fairly 
recent introduction (the largest individuals are 
ca. 4-5 years of age) or the inability of a typical 
river species to adapt to a lake environment is 
not clearly understood. 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 195 



Comparisons and Discussion 

Few thorough studies of quantitative and 
qualitative changes in naiad fauna resulting from 
artificial impoundment of fluvial systems and 
subsequent adaptation to lentic environment have 
been reported for North America. The pelecypod 
fauna from Lake Texoma in Texas and Oklahoma 
have been studied and reported (Riggs and Webb 
1965; White and White 1977) and some work had 
been conducted in the Red River prior to its im- 
poundment (Isely 1925). Conclusions set forth on 
the basis of the most recent studied suggests that 
"despite the many conditions seemingly working 
against the pelecypods of Lake Texoma, it can be 
said with some degree of confidence that they are 
flourishing when compared to their original di- 
versity and abundance" (White and White 1977: 
251). 

Unfortunately quantitative data are not avail- 
able to measure the strength of this observation. 
Variations in survey strategies preclude the pos- 
sibility of making direct comparisons from one 
report to the next. White and White (1977:248) 
note, for example, that "Tlie .study by Riggs and 
Webb (1956) found that the mussel populations 
of the lake were much more established than had 
been indicated previously; however, since they 
surveyed only one of the possible lake habitats, a 
loamy-sand substrate, the data could not be used 
to draw conclusions about the abundance of spe- 
cies throughout the entire lake." In fact Riggs 
and Webb (1956:200) report information that in- 
dicate the average naiad density was .39/m^ dur- 
ing 1953 while information provided for more 
varied habitats by White and White (1977:242) 
show that the mean density was .12/m^ during 
1975-1976. Only two of the stations collected by 
White and White (1977-stations 7 and 9) pro- 
duced as high a density (> .24/m^) as the station 
producing the lowest density during 1953 (Station 
8) when a portion of the lake was collected by 
Riggs and Webb (1956). The 1975-1976 collections 
did produce three species not collected by Riggs 
and Webb (1956), i.e. L. complanata, 0. refleoca 
and LampsiiLs teres. However, the significance of 
this observation is also rendered less impressive 
when one considers that White and White (1977) 
collected a surface area of over seven times as 
great as the area collected during 1953. 



Unlike the claims made for Lake Texoma, most 
observations made on naiads in the impound- 
ments of the larger, previously swift, streams and 
rivers of southeastern United States indicate that 
mussel populations have been drastically altered 
(e.g. Bates 1966; Stansbery 1964; Isom 1969). 
Bates (1966:235) notes, for example, that "Most of 
the large river forms which were characteristic of 
the pre-impoundment assemblage [in the Ten- 
nessee River] are now typically absent from these 
shallow water habitats" in the Kentucky Reser- 
voir. "The one exception noted here is Q. 
quadnda, which has successfully invaded these 
areas. Many juveniles of this species were col- 
lected from both the beach areas and the mud 
shallows indicating a much higher biotic poten- 
tial for this species than for the other Union- 
inae." In addition to Q. quadrida and C. parva, 
various species of Leptodea and Anodonta com- 
prised the dominant naiads recovered by Bates 
(1966). 

Pronounced changes in mussel population of 
unimpounded fluvial systems have also been well 
documented. In many of the streams of the Mid- 
west the overriding observation is that popula- 
tions have undergone various degrees of degradia- 
tion (e.g. Clark 1976; Matteson and Dexter 1966; 
Starrett 1971). One point of interest here is that 
all three of these reports on mussels in streams 
flowing through or bordering Illinois note the 
hardiness of Quadrida qimdnda despite siltation 
and pollution (Clark 1976:8; Matteson and Dexter 
1966:99; Starrett 1971:363). Also of interest is 
Clark's (1976:8) notation of recent increases in the 
occurrence of 0. reflexa in the Wabash River. 

A survey of pre-impoundment Lick and Sugar 
creeks in central Illinois was never undertaken. 
Consequently it is impossible to compare or con- 
trast species of the original lotic environment 
with those in the subsequent artificially produced 
lentic environment resulting from the construc- 
tion of Lake Springfield. However, mussel popula- 
tions of the lake were surveyed (1953) nearly two 
decades after impoundment (1935). Slightly over 
two decades later (1977) a survey of the same loci 
collected during 1953 was again undertaken. Re- 
sults of this second survey conclusively demon- 
strate that naiad density per unit area has gen- 
erally increased and that species diversity has 



196 THE NAUTILUS 



October 30, 1979 



Vol.94 (4) 



also taken place in Lake Springfield. In this 
respect the results of this second survey are 
similar to the claim for Lake Texoma, i.e. "in- 
creasing density and diversity within the lake" 
(White and White 1977:235). 

Seven of the ten species reported for Lake Tex- 
oma occur in Lake Springfield and seven of the 
12 species recovered from Lake Springfield are 
also found in Lake Texoma. Riggs and Webb 
(1956:201) report L. laevissirym and Q. qmidnda 
as the first and second respective most common 
species in Lake Te.xoma while White and White 
(1977:242) report L. laeinssima and A. yrandis as 
the two most numerous species. In the Lake 
Springfield populations for both 1953 and 1977, Q. 
quadrula was most numerous and L. laenssima 
the second most common of the Unionacea. Also, 
as in the case of Lake Springfield, 0. reflexa is a 
recent addition to Lake Te.xoma as it was not 
recovered by Riggs and Webb (1956) in 1953. 

While Q. fjuadritla has seemingly decreased in 
Lake Te.xoma, the species has actually increased 
in frequency in Lake Springfield. This seems to 
conform to some findings in both streams and 
rivers of the Midwest (Matteson and De.xter 1966) 
and lake environments in the South (Bates 1962). 
The manner in which Lake Springfield does not 
appear to compare favorably with many other 
reported populations in the Midwest and South- 
east is that there does not seem to be an overall 
degradation of naiad populations. Degradation of 
the population seems to be occurring in the upper 
reaches of Lake Springfield, as well as at the 
heads of inlets, but populations in the main body 
of the lake generally have thrived over the past 
two decades. However, as Lake Springfield con- 
tinues to silt in, it is expected that the naiad den- 
sity per unit area will continue to decrease and 
that A. (jrandis, A. imbecilis, and L. laevmima 
will continue to increase in relation to other 
species in the agrading portions of the lake. 

Hinge Anomalies 

Anomalies occurring in the form of transposed 
lateral hinge teeth have been noted in freshwater 
bivalves for over a centur\' (Agassiz 18.59: I^ea 
1860). Van der Schalie (1936) revised Lea's 1860 
list and included his own records of species ex- 
hibiting various combinations of transposed teeth 



which he accumulated during many years of in- 
tensive collecting. In addition to the eight species 
recorded by Lea, van der Schalie listed 18 others 
which represented (for all species) 72 anomalous 
individuals. None of the hinge variations de- 
scribed by these workers were found in species 
belonging to the genus Qiiadiida, so the oc- 
currence of transposed teeth in 13 individuals 
from the 1977 sample of Q. quadnda collected in 
Lake Springfield is worthy of note. 

The normal dentition in species belonging to 
the family Unionidae consists of double lateral 
and pseudocardinal teeth in the left valve and a 
single lateral and pseudocardinal tooth in the 
right. At least five distinct variations were 
observed among the 13 anomalous individuals: 
single lateral in each valve (N = 3): double 
lateral in both valves (N=3): single lateral in 
left, double in right (N = 4): double lateral in left 
valve, partly treble in right (N = 2); treble 
laterals in both valves (N = l). One of the in- 
dividuals possessing a single lateral in the left 
valve and double lateral in the right is addi- 
tionally noteworthy because the i3seudocardinal 
teeth are also transposed. Whether or not re- 
versed or transposed hinge teeth in freshwater 
bivalves are a result of environmental or genetic 
factors is not clearly understood. However, the 
fact that such variations in hinge structure do oc- 
cur, even if uncommonly to rarely, is significant 
in relation to their use as characters in iden- 
tification and classification. Transposed hinge 
teeth were not noted in individuals of the other 
species from Lake Springfield. The anomalous 
specimens of Q. quadnda comprised approximate- 
ly one percent of the sample of that species. 

Summary 

Systematic surveys of the naiad fauna in the 
artificially formed lentic environment of bike 
Springfield of central Illinois were undertaken 
during 1953 and 1977. Comparable survey strat- 
egies employed during both sun'eys has made it 
possible to make direct comparisons of the naiad 
populations over a period of a quarter of a cen- 
tury. 

Both quantitative and qualitative changes have 
occurred in the naiad fauna. Generally, the naiad 
density per unit area h;is increased along the 



Vol.94 (4) 



October 30, 1979 



THE NAUTILUS 197 



shores of the main bt)dy of the lake while the 
density in the upper reaches of the lake and at 
the heads of the inlets has decreased. Com- 
mencerate with the decreased density that has oc- 
curred in these portions of the lake that have 
been agrading over the past 25 years are the 
changes in relative proportions of certain species 
of mussels; L. laevissima. A. grandis. and .4. ///;- 
bcciliti have increased with respect to other species 
in these habitats. 

Qualitative changes in the mussel fauna have 
also taken place in Lake Springfield. All of the 
species recovered during 1953 were also recorded 
during 1977. In addition, four species (i.e. C. par- 
va. T. truncata. 0. reflexa. and C. manilensw) 
have become newly established in the lake. Depo- 
sition of silt in the areas of entry of the feeder 
creeks appears to greatly inhibit the establish- 
ment and growth of naiads. With continued 
heavy silting at several locales in the lake, ac- 
cidental introduction or periodic stocking of fish, 
and with possible unforeseen changes in the pre- 
sent lake habitat, a future study of the mussels of 
Lake Springfield may well provide additional 
useful data relative to population dynamics 
under artificial conditions. 

ACKNOWLEDGMENTS 

We would like to thank Arthur E. Bogan, 
Department of Anthropology, University of Ten- 
nessee, Knoxville, for his assistance with the in- 
itial sorting and processing of the Lake Spring- 
field naiads. James R. Purdue, Illinois State 
Museum, Springfield, furnished the photograph in 
figure 2b and Marl in Roos, Illinois State 
Museum, Springfield, provided prints of all of the 
figures. 



LITERATURE CITED 

Agassiz. Louis. 1859. Notes on Unio ligamentimts reversed. 

P)vc. Boston Sue. Nat. Hisl. 7:166-167. 
Bates. John M. 1962. The impact of impoundment on the 

masse! fauna of Kentucky reservoir. Tennessee River. 

Amrr Midi Nat. m:2»>--m. 
Clark, Clarence F. 1976. The freshwater naiads of the lower 

Wabash River. Mt. Carmel. Illinois to the south. Sterkiana 

61:1-14. 
Isely. F. B. 1925. The fresh-water mussel fauna of eastern 

Oklahoma. Proc. Okla. Acad. Sri. 4:43-118. 
Isom, B. G. 1969. The mussel resource of the Tennessee River. 

Malacoloyia 7:397-425. 
Lea. Isaac. 1860. Proceedings of Acad. Nat. Sri,. Phil. 51-.53. 
Matteson. Max R. and Ralph W. Dexter. 1966. Changes in 

Pelecypod populations in Salt Fork of Big Vermilion River, 

Illinois 1918-1962. The Nautilus 79:96-101. 
Parmalee. Paul W. 19.55. .Some ecological aspects of the naiad 

fauna of Lake Springfield, Illinois. The Nautibi.^ 69:28-.34. 
. 1967. The fresh -water mussels of Illinois. III. St. 

Mj«. Pop. Sri. Sw. 8:1-108. 
and Walter E. Klippel. 1974. Freshwater mussels 



as a prehistoric food resource. .4mer. Antiq. 39:421-434. 
Riggs. C. D. and G. R. Webb. 19.56. The mussel population of 

an area of loamy-sand bottom of Lake Texoma. ,4 me?-. Midi. 

AVir. 56:197-203. 
Sinclair, R. M. 1971. Annotated bibliography on the exotic 

bivalve dirbicula in North America, 1900-1971. Sterkiana 

43:11-18. 
Stansbery, D. H. 1964. The Mussel (Muscle) Shoals of the Ten- 
nessee River revisited. Ann. Report Amer. Malacol. Union. 

1964:25-28. 
Starret, William C. 1971. A survey of the mussels (Unionacea) 

of the Illinois River: a polluted stream. HI. Nat. Ifist, Surv. 

Bull. 30:266-403. 
Thompson, Carl M. and Richard E. Sparks. 1977. The Asiatic 

Clam, Corbiculo manilenfds in the Illinois River. The 

Nautilus 91:31-36. 
van der Schalie, Henrv-. 1936. Transposed hinge teeth of North 

American naiades. The Nautilus 49:79-84. 
White. David S. and Susan J. White. 1977. Obser\-ations on 

the pelecvTxid fauna of Lake Texoma, Texas and Oklahoma, 

after more than 30 years impoundment. Southwest. Nat. 

22:2a5-254. 




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WAGNER AND ABBOTTS 

STANDARD CATALOG 

OF SHELLS 



Complete listings of the world's seashells, with 
geographical ranges, values, and World Size 
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^M)OR PRICE CHANCES - HUNDREDS MORE SPECIES 

AN ENLARGED EC5ITION OE A^TANDARD WORK COMPILED 
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The Most Important Shell Book You Will Ever Buy' 



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Now included is vour own personal catalog tor listing the 
specimens in vour collection Now vou can properly number 
your shells and permanently record their names, collecting data, 
field notes and values Designed by a museum expert, this 
looseleaf catalog is on durable, ruled sheets, with headings 17 in- 
ches (42 5 cm) across, andwith space for over 1,500 entries Ad- 
ditional packets of 1,500 blank entries available at cost ($3-00) 



Special Looseleaf Supplements Will Keep You Abreast 

of Rising or Falling Prices And Supply You With New 

Complete Family Listings international World Size Records 

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NEW! Now (he Catalog is Looseleaf! 

The durable, full-color, heavy-duty postbmder 
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plements and price changes can be quickly ad- 
ded Other journals such as Indo-PaQlUc 
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this binder Eilra binders available. ($ 8-95) 



been assembled from the latest scientific 
publications of such eminent malacologists as 
Abbott, Cernohosky, Rehder, Rosewaler, Emer- 
som. Clench, Powell, Ponder and many others 
Formerly called Van Nostrand's Standard 
Catalog of Shells Now published by American 
Ma/aco/og/s(s, Publishers. 




Destined to be a complete technical listing of all 
the living marine shells of the world The Stan 
UAKU Catalog also gives the current market 
values of the better-known species ISBN- O-915826-03-8 



Llnder the editorship of Robert I L Wagner and 
R Tucker Abbott, this monumental work has 



INDEXES TO THE NAUTILUS: 
GEOGRAPHICAL (Vols. 1-90) AND SCIENTIFIC NAMES (Vol. 61-90) 

A Vital Key to a Major Source of Original Research on Mollusca 



1. New Index to all the Scientific Namei^ appearing in 

volumes 61 through 90 (1947-1976). Contains 
31,400 page-references to 1.5,000 names. Cross in- 
dexed on the species-genus level. Covers 30 years. 

2. (jCdgmphwal Index to volumes 1 through 90 

(1886-1976). 90 years of American and foreign 
malacological research at your finger tips. The full 
titles of .5,200 articles are arranged geographically 
and chronologicaly into 50 U. S. states and 15 ma- 
jor foreign areas. Further divided into marine, 
land freshwater and fossil subjects. 



3. Antlmr Index to The Nautilus, volumes 1 through 
75. (gives full titles, date, volume and page 
reference; Anonymous and Obituaries listed 
separately). Prepared by Aurele La Rocque. 
Published 1963. We have acquired the last 1-50 
copies that were printed , and have had them 
bound. Obviously, this will soon be out-of-print 
and unavailable. Is your old one dogeared? 279 pp., 
paperbound. (postage paid) $8.00. 



Even if you don't own a complete set of THE NAUTILUS. 
these inde.xes will quickly tell you what volumes to borrow on 
interlibrary loan or what pages to have reproduced for your 
special research project. No one dares make a sun'ey or des- 
cribe a new speices without consulting this valuable tool. 



Both in one clothhiund volume. 8 x 10 ' : inches, 2.50 pp. $24.00 (postage paid). 



TELL YOUR LIBRARIAN and also GET ONE FOR YOUR HOME LIBRARY 

(KP'o discount on two or more copies on same order). 



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Mamtscripts: Authors are requested to follow 
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ences, 1401 Wilson Boulevard, Arlington, Va. 
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title at the top. Legends to photographs should 
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MOLLUSK VOUCHER SPECIMENS 



It is becoming increasingly important for 
future research purposes that an identified sam- 
pling of species mentioned in publications be 
deposited in a permanent, accessible museum 
specializing in mollusks. This is particularly 
true of mollusks used in physiological, medical, 
parasitological, ecological, and experimental 
projects. 



Several museums of natural history have ex- 
tensive modern facilities and equipment for the 
housing and curating of voucher specimens. 
Material should be accompanied by the identifica- 
tion, locality data and its bibliographic reference. 
There is no charge for this permanent curating 
service, and catalog numbers, if desired, will be 
sent to authors prior to publication. 



WANTED -OLD SHELL BOOKS 
Will pay good prices for libraries, second- 
hand books and reprints on mollusks, shells 
and conchology. Back numbers of The Nauti- 
lus, vols. 40-71 wanted, $1.50 each. Phone (1- 



305-725-2260) or write: R. Tucker Abbott, 
Americnn Malacologists. Inc.. P. 0. Box 2255 
Melbourne, FL 32901. Free appraisals. 



Ipii 

WH 17XY 



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